I have been looking around at other forums for Maya, but there are not any that I know of quite as active as this one.

I did run across this one that seems to have quite a few posts . . .

https://www.mayawizard.com/index.php

Highend3d has a pretty good forum. I found this site that has some pretty good tutorials on GUI construction with coding examples.

https://www.polyextrude.com/tutorials/MelScripting/