This is a minor issue.
When “Extend an screen” is used and the screen being extended is using Groovy, the template creates the new screen with a Java controller and you have to manually go back and fix the problem as the project will not compile anymore.
Just an FYI … this template does not feel right as the conventions it uses are suited more for extending Sys$ screens as opposed to app$ screens. You have to use it a couple of time to see what I mean. It’s not a big deal and hence why I have not spent time documenting what I am alluding to.