There’s a paragraph in the Fortnite Ecosystem v29.30 news post that mentions:
Expose UMG Widgets to Verse
You can now expose UMG widget assets to your Verse code. Then you can use your widget with Verse APIs to add it to a player’s UI, similar to how you previously worked with widgets that were defined all in Verse.
Weird thing, the v29.30 Release Notes linked in that news post doesn’t exist anymore.
I have another post reporting how the code does compile when writing a line such as Widget : UI.ExampleWidget = UI.ExampleWidget{} but will show an unrelated error when trying to Launch Session (which took me some time to understand what was wrong).