diff --git a/web/src/components/config-form/sectionExtras/CameraReviewClassification.tsx b/web/src/components/config-form/sectionExtras/CameraReviewClassification.tsx
index f716ef39c..ffe9b19b2 100644
--- a/web/src/components/config-form/sectionExtras/CameraReviewClassification.tsx
+++ b/web/src/components/config-form/sectionExtras/CameraReviewClassification.tsx
@@ -3,6 +3,7 @@ import { Link } from "react-router-dom";
 import { Trans, useTranslation } from "react-i18next";
 import cloneDeep from "lodash/cloneDeep";
 import get from "lodash/get";
+import isEqual from "lodash/isEqual";
 import set from "lodash/set";
 import { LuExternalLink } from "react-icons/lu";
 import { MdCircle } from "react-icons/md";
@@ -36,6 +37,9 @@ export default function CameraReviewClassification({
   const { getLocaleDocUrl } = useDocDomain();
   const cameraName = formContext?.cameraName ?? selectedCamera;
   const fullFormData = formContext?.formData as JsonObject | undefined;
+  const baselineFormData = formContext?.baselineFormData as
+    | JsonObject
+    | undefined;
   const cameraConfig = formContext?.fullCameraConfig;
 
   const alertsZones = useMemo(
@@ -47,6 +51,25 @@ export default function CameraReviewClassification({
     [fullFormData],
   );
 
+  // Track whether zones have been modified from baseline for label coloring
+  const alertsZonesModified = useMemo(() => {
+    if (!baselineFormData) return false;
+    const baseline = getRequiredZones(
+      baselineFormData,
+      "alerts.required_zones",
+    );
+    return !isEqual(alertsZones, baseline);
+  }, [alertsZones, baselineFormData]);
+
+  const detectionsZonesModified = useMemo(() => {
+    if (!baselineFormData) return false;
+    const baseline = getRequiredZones(
+      baselineFormData,
+      "detections.required_zones",
+    );
+    return !isEqual(detectionsZones, baseline);
+  }, [detectionsZones, baselineFormData]);
+
   const [selectDetections, setSelectDetections] = useState(
     detectionsZones.length > 0,
   );
@@ -192,7 +215,12 @@ export default function CameraReviewClassification({
           {zones && zones.length > 0 ? (
             <>
               <div className="mb-2">
-                <Label className="flex flex-row items-center text-base">
+                <Label
+                  className={cn(
+                    "flex flex-row items-center text-base",
+                    alertsZonesModified && "text-danger",
+                  )}
+                >
                   <Trans ns="views/settings">cameraReview.review.alerts</Trans>
                   <MdCircle className="ml-3 size-2 text-severity_alert" />
                 </Label>
@@ -255,7 +283,12 @@ export default function CameraReviewClassification({
           {zones && zones.length > 0 && (
             <>
               <div className="mb-2">
-                <Label className="flex flex-row items-center text-base">
+                <Label
+                  className={cn(
+                    "flex flex-row items-center text-base",
+                    detectionsZonesModified && "text-danger",
+                  )}
+                >
                   <Trans ns="views/settings">
                     cameraReview.review.detections
                   </Trans>
diff --git a/web/src/components/config-form/sections/BaseSection.tsx b/web/src/components/config-form/sections/BaseSection.tsx
index 6a76f358c..13c8aad93 100644
--- a/web/src/components/config-form/sections/BaseSection.tsx
+++ b/web/src/components/config-form/sections/BaseSection.tsx
@@ -192,6 +192,14 @@ export function ConfigSection({
   // Use pending data from parent if available, otherwise use local state
   const [localPendingData, setLocalPendingData] =
     useState<ConfigSectionData | null>(null);
+  const [pendingOverrides, setPendingOverrides] = useState<
+    JsonValue | undefined
+  >(undefined);
+  const [dirtyOverrides, setDirtyOverrides] = useState<JsonValue | undefined>(
+    undefined,
+  );
+  const [baselineFormData, setBaselineFormData] =
+    useState<ConfigSectionData | null>(null);
 
   const pendingData =
     pendingDataBySection !== undefined
@@ -314,17 +322,31 @@ export function ConfigSection({
     [level, schemaDefaults, sectionPath, modifiedSchema],
   );
 
+  const compareBaseData = useMemo(
+    () => sanitizeSectionData(rawFormData as ConfigSectionData),
+    [rawFormData, sanitizeSectionData],
+  );
+
   // Clear pendingData whenever formData changes (e.g., from server refresh)
   // This prevents RJSF's initial onChange call from being treated as a user edit
   // Only clear if pendingData is managed locally (not by parent)
   useEffect(() => {
     if (!pendingData) {
       isInitializingRef.current = true;
+      setPendingOverrides(undefined);
+      setDirtyOverrides(undefined);
+      setBaselineFormData(cloneDeep(formData as ConfigSectionData));
     }
     if (onPendingDataChange === undefined) {
       setPendingData(null);
     }
-  }, [formData, pendingData, setPendingData, onPendingDataChange]);
+  }, [
+    formData,
+    pendingData,
+    setPendingData,
+    setBaselineFormData,
+    onPendingDataChange,
+  ]);
 
   useEffect(() => {
     if (isResettingRef.current) {
@@ -435,58 +457,98 @@ export function ConfigSection({
     (data: unknown) => {
       if (isResettingRef.current) {
         setPendingData(null);
+        setPendingOverrides(undefined);
         return;
       }
       if (!data || typeof data !== "object") {
         setPendingData(null);
+        setPendingOverrides(undefined);
         return;
       }
       const sanitizedData = sanitizeSectionData(data as ConfigSectionData);
-      // When the server-stored `rawSectionValue` for `motion` global is
-      // actually `null` we must preserve that `null` sentinel for base
-      // comparisons. `isMotionGlobal` signals that the stored value is
-      // intentionally null (meaning "no global override provided"), so the
-      // baseline used by `buildOverrides` should be `null` rather than an
-      // object. This keeps the UI from treating the form-populated default
-      // object as a user edit on initial render.
-      const isMotionGlobal =
-        sectionPath === "motion" &&
-        level === "global" &&
-        rawSectionValue === null;
-      const rawData = isMotionGlobal
-        ? null
-        : sanitizeSectionData(rawFormData as ConfigSectionData);
+      let nextBaselineFormData = baselineFormData ?? formData;
       const overrides = buildOverrides(
         sanitizedData,
-        rawData,
+        compareBaseData,
         effectiveSchemaDefaults,
       );
+      setPendingOverrides(overrides as JsonValue | undefined);
       if (isInitializingRef.current && !pendingData) {
         isInitializingRef.current = false;
+        if (!baselineFormData) {
+          // Always use formData (server data + schema defaults) for the
+          // baseline snapshot, NOT sanitizedData from the onChange callback.
+          // If a custom component (e.g., zone checkboxes) triggers onChange
+          // before RJSF's initial onChange, sanitizedData would include the
+          // user's modification, corrupting the baseline.
+          const baselineSnapshot = cloneDeep(formData as ConfigSectionData);
+          setBaselineFormData(baselineSnapshot);
+          nextBaselineFormData = baselineSnapshot;
+        }
         if (overrides === undefined) {
           setPendingData(null);
+          setPendingOverrides(undefined);
+          setDirtyOverrides(undefined);
           return;
         }
       }
+      const dirty = buildOverrides(
+        sanitizedData,
+        nextBaselineFormData,
+        undefined,
+      );
+      setDirtyOverrides(dirty as JsonValue | undefined);
       if (overrides === undefined) {
         setPendingData(null);
+        setPendingOverrides(undefined);
+        setDirtyOverrides(undefined);
         return;
       }
       setPendingData(sanitizedData);
     },
     [
       pendingData,
-      level,
-      sectionPath,
-      rawSectionValue,
-      rawFormData,
+      compareBaseData,
       sanitizeSectionData,
       buildOverrides,
       effectiveSchemaDefaults,
       setPendingData,
+      setPendingOverrides,
+      setDirtyOverrides,
+      baselineFormData,
+      setBaselineFormData,
+      formData,
     ],
   );
 
+  const currentFormData = pendingData || formData;
+  const effectiveBaselineFormData = baselineFormData ?? formData;
+
+  const currentOverrides = useMemo(() => {
+    if (!currentFormData || typeof currentFormData !== "object") {
+      return undefined;
+    }
+    const sanitizedData = sanitizeSectionData(
+      currentFormData as ConfigSectionData,
+    );
+    return buildOverrides(
+      sanitizedData,
+      compareBaseData,
+      effectiveSchemaDefaults,
+    );
+  }, [
+    currentFormData,
+    sanitizeSectionData,
+    buildOverrides,
+    compareBaseData,
+    effectiveSchemaDefaults,
+  ]);
+
+  const effectiveOverrides = pendingData
+    ? (pendingOverrides ?? currentOverrides)
+    : undefined;
+  const uiOverrides = dirtyOverrides ?? effectiveOverrides;
+
   const requiresRestartForOverrides = useCallback(
     (overrides: unknown) => {
       if (sectionConfig.restartRequired === undefined) {
@@ -511,8 +573,10 @@ export function ConfigSection({
   const handleReset = useCallback(() => {
     isResettingRef.current = true;
     setPendingData(null);
+    setPendingOverrides(undefined);
+    setDirtyOverrides(undefined);
     setFormKey((prev) => prev + 1);
-  }, [setPendingData]);
+  }, [setPendingData, setPendingOverrides, setDirtyOverrides]);
 
   // Handle save button click
   const handleSave = useCallback(async () => {
@@ -808,7 +872,7 @@ export function ConfigSection({
       <ConfigForm
         key={formKey}
         schema={modifiedSchema}
-        formData={pendingData || formData}
+        formData={currentFormData}
         onChange={handleChange}
         fieldOrder={sectionConfig.fieldOrder}
         fieldGroups={sectionConfig.fieldGroups}
@@ -827,7 +891,9 @@ export function ConfigSection({
           globalValue,
           cameraValue,
           hasChanges,
-          formData: (pendingData || formData) as ConfigSectionData,
+          overrides: uiOverrides as JsonValue | undefined,
+          formData: currentFormData as ConfigSectionData,
+          baselineFormData: effectiveBaselineFormData as ConfigSectionData,
           onFormDataChange: (data: ConfigSectionData) => handleChange(data),
           // For widgets that need access to full camera config (e.g., zone names)
           fullCameraConfig:
@@ -845,6 +911,7 @@ export function ConfigSection({
           renderers: wrappedRenderers,
           sectionDocs: sectionConfig.sectionDocs,
           fieldDocs: sectionConfig.fieldDocs,
+          hiddenFields: sectionConfig.hiddenFields,
         }}
       />
 
diff --git a/web/src/components/config-form/theme/fields/LayoutGridField.tsx b/web/src/components/config-form/theme/fields/LayoutGridField.tsx
index 52c1288ee..54b028ba3 100644
--- a/web/src/components/config-form/theme/fields/LayoutGridField.tsx
+++ b/web/src/components/config-form/theme/fields/LayoutGridField.tsx
@@ -78,11 +78,15 @@
  */
 
 import type { FieldProps, ObjectFieldTemplateProps } from "@rjsf/utils";
-import { useState } from "react";
+import { useCallback, useMemo, useState } from "react";
 import { useTranslation } from "react-i18next";
 import { cn } from "@/lib/utils";
 import { ConfigFormContext } from "@/types/configForm";
-import { getDomainFromNamespace, humanizeKey } from "../utils/i18n";
+import {
+  getDomainFromNamespace,
+  hasOverrideAtPath,
+  humanizeKey,
+} from "../utils";
 import { AddPropertyButton, AdvancedCollapsible } from "../components";
 
 type LayoutGridColumnConfig = {
@@ -126,7 +130,6 @@ function GridLayoutObjectFieldTemplate(
     readonly,
   } = props;
   const formContext = registry?.formContext as ConfigFormContext | undefined;
-  const [showAdvanced, setShowAdvanced] = useState(false);
   const { t } = useTranslation(["common", "config/groups"]);
 
   // Use the original ObjectFieldTemplate passed as parameter, not from registry
@@ -145,11 +148,11 @@ function GridLayoutObjectFieldTemplate(
   const useGridForAdvanced = layoutGridOptions.useGridForAdvanced ?? true;
   const groupDefinitions =
     (uiSchema?.["ui:groups"] as Record<string, string[]> | undefined) || {};
+  const overrides = formContext?.overrides;
+  const fieldPath = props.fieldPathId.path;
 
-  // If no layout grid is defined, use the default template
-  if (layoutGrid.length === 0) {
-    return <ObjectFieldTemplate {...props} />;
-  }
+  const isPathModified = (path: Array<string | number>) =>
+    hasOverrideAtPath(overrides, path, formContext?.formData);
 
   // Override the properties rendering with grid layout
   const isHiddenProp = (prop: (typeof properties)[number]) =>
@@ -164,6 +167,15 @@ function GridLayoutObjectFieldTemplate(
   const regularProps = visibleProps.filter(
     (p) => p.content.props.uiSchema?.["ui:options"]?.advanced !== true,
   );
+  const hasModifiedAdvanced = advancedProps.some((prop) =>
+    isPathModified([...fieldPath, prop.name]),
+  );
+  const [showAdvanced, setShowAdvanced] = useState(hasModifiedAdvanced);
+
+  // If no layout grid is defined, use the default template
+  if (layoutGrid.length === 0) {
+    return <ObjectFieldTemplate {...props} />;
+  }
 
   const domain = getDomainFromNamespace(formContext?.i18nNamespace);
   const sectionI18nPrefix = formContext?.sectionI18nPrefix;
@@ -518,14 +530,22 @@ export function LayoutGridField(props: FieldProps) {
 
   // Create a modified registry with our custom template
   // But we'll pass the original template to it to prevent circular reference
-  const modifiedRegistry = {
-    ...registry,
-    templates: {
-      ...registry.templates,
-      ObjectFieldTemplate: (tProps: ObjectFieldTemplateProps) =>
-        GridLayoutObjectFieldTemplate(tProps, originalObjectFieldTemplate),
-    },
-  };
+  const gridObjectFieldTemplate = useCallback(
+    (tProps: ObjectFieldTemplateProps) =>
+      GridLayoutObjectFieldTemplate(tProps, originalObjectFieldTemplate),
+    [originalObjectFieldTemplate],
+  );
+
+  const modifiedRegistry = useMemo(
+    () => ({
+      ...registry,
+      templates: {
+        ...registry.templates,
+        ObjectFieldTemplate: gridObjectFieldTemplate,
+      },
+    }),
+    [registry, gridObjectFieldTemplate],
+  );
 
   // Delegate to ObjectField with the modified registry
   return (
diff --git a/web/src/components/config-form/theme/templates/FieldTemplate.tsx b/web/src/components/config-form/theme/templates/FieldTemplate.tsx
index 099aca8d6..12a722587 100644
--- a/web/src/components/config-form/theme/templates/FieldTemplate.tsx
+++ b/web/src/components/config-form/theme/templates/FieldTemplate.tsx
@@ -19,8 +19,13 @@ import { useDocDomain } from "@/hooks/use-doc-domain";
 import {
   buildTranslationPath,
   getFilterObjectLabel,
+  hasOverrideAtPath,
   humanizeKey,
-} from "../utils/i18n";
+  normalizeFieldValue,
+} from "../utils";
+import { normalizeOverridePath } from "../utils/overrides";
+import get from "lodash/get";
+import isEqual from "lodash/isEqual";
 
 function _isArrayItemInAdditionalProperty(
   pathSegments: Array<string | number>,
@@ -66,6 +71,7 @@ export function FieldTemplate(props: FieldTemplateProps) {
     onRemoveProperty,
     rawDescription,
     rawErrors,
+    formData: fieldFormData,
     disabled,
     readonly,
   } = props;
@@ -131,6 +137,30 @@ export function FieldTemplate(props: FieldTemplateProps) {
     sectionI18nPrefix,
     formContext,
   );
+  const fieldPath = fieldPathId.path;
+  const overrides = formContext?.overrides;
+  const baselineFormData = formContext?.baselineFormData;
+  const normalizedFieldPath = normalizeOverridePath(
+    fieldPath,
+    formContext?.formData,
+  );
+  let baselineValue = baselineFormData
+    ? get(baselineFormData, normalizedFieldPath)
+    : undefined;
+  if (baselineValue === undefined || baselineValue === null) {
+    if (schema.default !== undefined && schema.default !== null) {
+      baselineValue = schema.default;
+    }
+  }
+  const isBaselineModified =
+    baselineFormData !== undefined &&
+    !isEqual(
+      normalizeFieldValue(fieldFormData),
+      normalizeFieldValue(baselineValue),
+    );
+  const isModified = baselineFormData
+    ? isBaselineModified
+    : hasOverrideAtPath(overrides, fieldPath, formContext?.formData);
   const filterObjectLabel = getFilterObjectLabel(pathSegments);
   const translatedFilterObjectLabel = filterObjectLabel
     ? getTranslatedLabel(filterObjectLabel, "object")
@@ -364,6 +394,7 @@ export function FieldTemplate(props: FieldTemplateProps) {
                 htmlFor={id}
                 className={cn(
                   "text-sm font-medium",
+                  isModified && "text-danger",
                   errors &&
                     errors.props?.errors?.length > 0 &&
                     "text-destructive",
@@ -378,7 +409,13 @@ export function FieldTemplate(props: FieldTemplateProps) {
             <div className="flex w-full items-center justify-between gap-4">
               <div className="space-y-0.5">
                 {displayLabel && finalLabel && (
-                  <Label htmlFor={id} className="text-sm font-medium">
+                  <Label
+                    htmlFor={id}
+                    className={cn(
+                      "text-sm font-medium",
+                      isModified && "text-danger",
+                    )}
+                  >
                     {finalLabel}
                     {required && (
                       <span className="ml-1 text-destructive">*</span>
diff --git a/web/src/components/config-form/theme/templates/ObjectFieldTemplate.tsx b/web/src/components/config-form/theme/templates/ObjectFieldTemplate.tsx
index ca6c04797..d8c82d657 100644
--- a/web/src/components/config-form/theme/templates/ObjectFieldTemplate.tsx
+++ b/web/src/components/config-form/theme/templates/ObjectFieldTemplate.tsx
@@ -6,7 +6,7 @@ import {
   CollapsibleContent,
   CollapsibleTrigger,
 } from "@/components/ui/collapsible";
-import { Children, useState } from "react";
+import { Children, useState, useEffect } from "react";
 import type { ReactNode } from "react";
 import { LuChevronDown, LuChevronRight } from "react-icons/lu";
 import { useTranslation } from "react-i18next";
@@ -15,10 +15,12 @@ import { getTranslatedLabel } from "@/utils/i18n";
 import { ConfigFormContext } from "@/types/configForm";
 import {
   buildTranslationPath,
+  getDomainFromNamespace,
   getFilterObjectLabel,
   humanizeKey,
-  getDomainFromNamespace,
-} from "../utils/i18n";
+  isSubtreeModified,
+} from "../utils";
+import get from "lodash/get";
 import { AddPropertyButton, AdvancedCollapsible } from "../components";
 
 export function ObjectFieldTemplate(props: ObjectFieldTemplateProps) {
@@ -38,8 +40,115 @@ export function ObjectFieldTemplate(props: ObjectFieldTemplateProps) {
 
   // Check if this is a root-level object
   const isRoot = registry?.rootSchema === schema;
+  const overrides = formContext?.overrides;
+  const baselineFormData = formContext?.baselineFormData;
+  const hiddenFields = formContext?.hiddenFields;
+  const fieldPath = props.fieldPathId.path;
 
-  const [isOpen, setIsOpen] = useState(false);
+  // Strip fields from an object that should be excluded from modification
+  // detection: fields listed in hiddenFields (stripped from baseline by
+  // sanitizeSectionData) and fields with ui:widget=hidden in uiSchema
+  // (managed by custom components, not the standard form).
+  const stripExcludedFields = (
+    data: unknown,
+    path: Array<string | number>,
+  ): unknown => {
+    if (
+      !data ||
+      typeof data !== "object" ||
+      Array.isArray(data) ||
+      data === null
+    ) {
+      return data;
+    }
+    const result = { ...(data as Record<string, unknown>) };
+    const pathStrings = path.map(String);
+
+    // Strip hiddenFields that match the current path prefix
+    if (hiddenFields) {
+      for (const hidden of hiddenFields) {
+        const parts = hidden.split(".");
+        if (
+          parts.length === pathStrings.length + 1 &&
+          pathStrings.every((s, i) => s === parts[i])
+        ) {
+          delete result[parts[parts.length - 1]];
+        }
+      }
+    }
+
+    // Strip ui:widget=hidden fields from uiSchema at this level
+    if (uiSchema) {
+      // Navigate to the uiSchema subtree matching the relative path
+      let subUiSchema = uiSchema;
+      const relativePath = path.slice(fieldPath.length);
+      for (const segment of relativePath) {
+        if (
+          typeof segment === "string" &&
+          subUiSchema &&
+          typeof subUiSchema[segment] === "object"
+        ) {
+          subUiSchema = subUiSchema[segment] as typeof uiSchema;
+        } else {
+          subUiSchema = undefined as unknown as typeof uiSchema;
+          break;
+        }
+      }
+      if (subUiSchema && typeof subUiSchema === "object") {
+        for (const [key, propSchema] of Object.entries(subUiSchema)) {
+          if (
+            !key.startsWith("ui:") &&
+            typeof propSchema === "object" &&
+            propSchema !== null &&
+            (propSchema as Record<string, unknown>)["ui:widget"] === "hidden"
+          ) {
+            delete result[key];
+          }
+        }
+      }
+    }
+
+    return result;
+  };
+
+  // Use props.formData (always up-to-date from RJSF) rather than
+  // formContext.formData which can be stale in parent templates.
+  const checkSubtreeModified = (path: Array<string | number>): boolean => {
+    // Compute relative path from this object's fieldPath to get the
+    // value from props.formData (which represents this object's data)
+    const relativePath = path.slice(fieldPath.length);
+    let currentValue =
+      relativePath.length > 0 ? get(formData, relativePath) : formData;
+
+    // Strip hidden/excluded fields from the RJSF data before comparing
+    // against the baseline (which already has these stripped)
+    currentValue = stripExcludedFields(currentValue, path);
+
+    let baselineValue =
+      path.length > 0 ? get(baselineFormData, path) : baselineFormData;
+    // Also strip hidden/excluded fields from the baseline so that fields
+    // managed by custom components (e.g. required_zones with ui:widget=hidden)
+    // don't cause false modification detection.
+    baselineValue = stripExcludedFields(baselineValue, path);
+
+    return isSubtreeModified(
+      currentValue,
+      baselineValue,
+      overrides,
+      path,
+      formContext?.formData,
+    );
+  };
+
+  const hasModifiedDescendants = checkSubtreeModified(fieldPath);
+  const [isOpen, setIsOpen] = useState(hasModifiedDescendants);
+
+  // Auto-expand collapsible when modifications are detected
+  useEffect(() => {
+    if (hasModifiedDescendants) {
+      setIsOpen(true);
+    }
+  }, [hasModifiedDescendants]);
 
   const isCameraLevel = formContext?.level === "camera";
   const effectiveNamespace = isCameraLevel ? "config/cameras" : "config/global";
@@ -71,8 +180,17 @@ export function ObjectFieldTemplate(props: ObjectFieldTemplateProps) {
   const regularProps = visibleProps.filter(
     (p) => p.content.props.uiSchema?.["ui:options"]?.advanced !== true,
   );
+  const hasModifiedAdvanced = advancedProps.some((prop) =>
+    checkSubtreeModified([...fieldPath, prop.name]),
+  );
+  const [showAdvanced, setShowAdvanced] = useState(hasModifiedAdvanced);
 
-  const [showAdvanced, setShowAdvanced] = useState(false);
+  // Auto-expand advanced section when modifications are detected
+  useEffect(() => {
+    if (hasModifiedAdvanced) {
+      setShowAdvanced(true);
+    }
+  }, [hasModifiedAdvanced]);
   const { children } = props as ObjectFieldTemplateProps & {
     children?: ReactNode;
   };
@@ -290,7 +408,14 @@ export function ObjectFieldTemplate(props: ObjectFieldTemplateProps) {
           <CardHeader className="cursor-pointer p-4 transition-colors hover:bg-muted/50">
             <div className="flex items-center justify-between">
               <div>
-                <CardTitle className="text-sm">{inferredLabel}</CardTitle>
+                <CardTitle
+                  className={cn(
+                    "text-sm",
+                    hasModifiedDescendants && "text-danger",
+                  )}
+                >
+                  {inferredLabel}
+                </CardTitle>
                 {inferredDescription && (
                   <p className="mt-1 text-xs text-muted-foreground">
                     {inferredDescription}
diff --git a/web/src/components/config-form/theme/utils/index.ts b/web/src/components/config-form/theme/utils/index.ts
index 45ede5eaf..c79e339fa 100644
--- a/web/src/components/config-form/theme/utils/index.ts
+++ b/web/src/components/config-form/theme/utils/index.ts
@@ -8,3 +8,10 @@ export {
   humanizeKey,
   getDomainFromNamespace,
 } from "./i18n";
+
+export { getOverrideAtPath, hasOverrideAtPath } from "./overrides";
+export {
+  deepNormalizeValue,
+  normalizeFieldValue,
+  isSubtreeModified,
+} from "./overrides";
diff --git a/web/src/components/config-form/theme/utils/overrides.ts b/web/src/components/config-form/theme/utils/overrides.ts
new file mode 100644
index 000000000..9e94fbdf2
--- /dev/null
+++ b/web/src/components/config-form/theme/utils/overrides.ts
@@ -0,0 +1,128 @@
+import get from "lodash/get";
+import isEqual from "lodash/isEqual";
+import { isJsonObject } from "@/lib/utils";
+import type { JsonValue } from "@/types/configForm";
+
+export const getOverrideAtPath = (
+  overrides: JsonValue | undefined,
+  path: Array<string | number>,
+) => {
+  if (overrides === undefined || overrides === null) {
+    return undefined;
+  }
+
+  if (isJsonObject(overrides) || Array.isArray(overrides)) {
+    return get(overrides, path);
+  }
+
+  return path.length === 0 ? overrides : undefined;
+};
+
+export const normalizeOverridePath = (
+  path: Array<string | number>,
+  data: JsonValue | undefined,
+) => {
+  if (data === undefined || data === null) {
+    return path;
+  }
+
+  const normalized: Array<string | number> = [];
+  let cursor: JsonValue | undefined = data;
+
+  for (const segment of path) {
+    if (typeof segment === "number") {
+      if (Array.isArray(cursor)) {
+        normalized.push(segment);
+        cursor = cursor[segment] as JsonValue | undefined;
+      }
+      continue;
+    }
+
+    normalized.push(segment);
+
+    if (isJsonObject(cursor) || Array.isArray(cursor)) {
+      cursor = (cursor as Record<string, JsonValue>)[segment];
+    } else {
+      cursor = undefined;
+    }
+  }
+
+  return normalized;
+};
+
+export const hasOverrideAtPath = (
+  overrides: JsonValue | undefined,
+  path: Array<string | number>,
+  contextData?: JsonValue,
+) => {
+  const normalizedPath = contextData
+    ? normalizeOverridePath(path, contextData)
+    : path;
+  const value = getOverrideAtPath(overrides, normalizedPath);
+  if (value !== undefined) {
+    return true;
+  }
+  const shouldFallback =
+    normalizedPath.length !== path.length ||
+    normalizedPath.some((segment, index) => segment !== path[index]);
+  if (!shouldFallback) {
+    return false;
+  }
+  return getOverrideAtPath(overrides, path) !== undefined;
+};
+
+/**
+ * Deep normalization for form data comparison. Strips null, undefined,
+ * and empty-string values from objects and arrays so that RJSF-injected
+ * schema defaults (e.g., `mask: null`) don't cause false positives
+ * against a baseline that lacks those keys.
+ */
+export const deepNormalizeValue = (value: unknown): unknown => {
+  if (value === null || value === undefined || value === "") return undefined;
+  if (Array.isArray(value)) return value.map(deepNormalizeValue);
+  if (typeof value === "object" && value !== null) {
+    const result: Record<string, unknown> = {};
+    for (const [k, v] of Object.entries(value as Record<string, unknown>)) {
+      const normalized = deepNormalizeValue(v);
+      if (normalized !== undefined) {
+        result[k] = normalized;
+      }
+    }
+    return Object.keys(result).length > 0 ? result : undefined;
+  }
+  return value;
+};
+
+/**
+ * Shallow normalization for individual field values.
+ * Treats null and empty-string as equivalent to undefined.
+ */
+export const normalizeFieldValue = (value: unknown): unknown =>
+  value === null || value === "" ? undefined : value;
+
+/**
+ * Check whether a subtree of form data has been modified relative to
+ * the baseline. Uses deep normalization to ignore RJSF-injected null/empty
+ * schema defaults.
+ *
+ * @param currentData - The current value at the subtree (from props.formData)
+ * @param baselineData - The baseline value at the subtree (from formContext.baselineFormData)
+ * @param overrides - Fallback: the overrides object from formContext
+ * @param path - The full field path for the fallback override check
+ * @param contextData - The full form data for normalizing the override path
+ */
+export const isSubtreeModified = (
+  currentData: unknown,
+  baselineData: unknown,
+  overrides: JsonValue | undefined,
+  path: Array<string | number>,
+  contextData?: JsonValue,
+): boolean => {
+  if (baselineData !== undefined || currentData !== undefined) {
+    return !isEqual(
+      deepNormalizeValue(currentData),
+      deepNormalizeValue(baselineData),
+    );
+  }
+  return hasOverrideAtPath(overrides, path, contextData);
+};
diff --git a/web/src/lib/config-schema/transformer.ts b/web/src/lib/config-schema/transformer.ts
index 8681266fa..d076b4167 100644
--- a/web/src/lib/config-schema/transformer.ts
+++ b/web/src/lib/config-schema/transformer.ts
@@ -606,7 +606,10 @@ export function extractSchemaSection(
 }
 
 /**
- * Merges default values from schema into form data
+ * Merges default values from schema into form data.
+ *
+ * Handles anyOf/oneOf schemas (e.g., `anyOf: [MotionConfig, null]`) by
+ * finding the non-null object branch and applying its property defaults.
  */
 export function applySchemaDefaults(
   schema: RJSFSchema,
@@ -615,12 +618,32 @@ export function applySchemaDefaults(
   const result = { ...formData };
   const schemaObj = schema as Record<string, unknown>;
 
-  if (!isSchemaObject(schemaObj.properties)) {
+  // Resolve properties, falling back to the non-null object branch of
+  // anyOf/oneOf schemas when top-level properties are not present.
+  let properties = schemaObj.properties;
+  if (!isSchemaObject(properties)) {
+    const branches = (schemaObj.anyOf ?? schemaObj.oneOf) as
+      | unknown[]
+      | undefined;
+    if (Array.isArray(branches)) {
+      const objectBranch = branches.find(
+        (s) =>
+          isSchemaObject(s) &&
+          (s as Record<string, unknown>).type !== "null" &&
+          isSchemaObject((s as Record<string, unknown>).properties),
+      ) as Record<string, unknown> | undefined;
+      if (objectBranch) {
+        properties = objectBranch.properties;
+      }
+    }
+  }
+
+  if (!isSchemaObject(properties)) {
     return result;
   }
 
   for (const [key, prop] of Object.entries(
-    schemaObj.properties as Record<string, unknown>,
+    properties as Record<string, unknown>,
   )) {
     if (!isSchemaObject(prop)) continue;
 
diff --git a/web/src/types/configForm.ts b/web/src/types/configForm.ts
index 02e718060..93659d328 100644
--- a/web/src/types/configForm.ts
+++ b/web/src/types/configForm.ts
@@ -18,8 +18,11 @@ export type ConfigFormContext = {
   cameraName?: string;
   globalValue?: JsonValue;
   cameraValue?: JsonValue;
+  overrides?: JsonValue;
   hasChanges?: boolean;
   formData?: JsonObject;
+  baselineFormData?: JsonObject;
+  hiddenFields?: string[];
   onFormDataChange?: (data: ConfigSectionData) => void;
   fullCameraConfig?: CameraConfig;
   fullConfig?: FrigateConfig;