i just went to try this out but i get a shed load of errors on 4.2.2 any chance you can check to see if works with the stable version, tried to fix with gpt but just adds more errors.
e.g.
In Godot 4, the @export_custom function has been removed, and the @export annotation is now used for exposing properties to the editor.
then also the testscene does not work says it has parsing issues, i checked scripts seems debug got loads of errors.
im very intrested in getting this working for my project if you can check would be great, Ultimate-Platformer-Controller-2D seems to work fine