Currently, if you attempt to apply a Layout Transform to a TabItem, the Studio UI allows it, as well as shows an asterisk in the file indicating that changes can be made, and that those changes can be saved.

However, modifying the Property results in no changes to the Element on-Stage, and upon inspecting the XAML, the value input in Studio is not reflected in the XAML. It appears that the change is only logged in Studio's UI to no effect anywhere else.

My assumption is that this is because the TabItem cannot be Layout Transformed due to the nature of how its controlled within a TabControl. However, the coupling of having the Layout Transform Properties present and enabled, as well as being able to receive values, and showing a change in the file via the asterisk, can lead to believe otherwise.

Repro Steps;
1) Create a Project with a MainPage.xaml
2) Introduce a TabControl to the Page.
3) From the Navigator, select either of the default TabItems, and in its Properties, set a Layout Transform Translate X or Transalte Y of your choosing.
Observe how the value is input, but no movement is observed on-Stage.
Observe how the MainPage.xaml tab is showing an asterisk indicating a change has been made to the file.

4) Save the file, and open it in VSCode.
Observer how there are no traces of the Layout Transform that was just input in Studio.

Expected Results:
Likely, the Layout Transform section should be not present, or disabled (either entire section, or just the values greyed out in the input field) for Elements that don't support the operation.

Expected Results:
Studio likely should not show a change to the file, via an asterisk, for a file that has not had its XAML modified.