When entering Prefab Mode in Context we show the values of the Prefab instance on the Prefab Asset objects and disable the controls in the Inspector so the user cannot edit these (they are patched so should be non-editable).
This works correctly when using IMGUI but UIToolkit does not disable these controls yet.
IMGUI correctly disables patched properties:
UIToolkit does not disable the controls for patched properties
This feature has existed since Unity 2020.1
Note that the disabled properties also have a tooltip to help the user to understand why they are disabled:
Repro:
1) Open My Project (23)
2) Open the Sample Scene
3) Select the GameObject prefab instance in the scene and notice its overrides on "User Scripts" component in the Inspector
4) In the Hierarchy click the button with '>' for 'GameObject' to enter Prefab Mode In Context
5) Notice that the the patched properties are not disabled when using UIToolkit
Expected: Controls are disabled as when using IMGUI Default Inspector.
See video attached in comment below.