I occasionally lurk the dungeon synth forum. Not sure if that counts as 'use'.

https://dungeonsynth.proboards.com/

yes

sometimes for technical questions/work related stuff

I'm no longer active, but permies.com is a good permaculture forum. I go there for research on occasion

Autodesk forums if those count

I lurk the IDM fourm still. Lots of good sound design stuff there.

https://boards.4chan.org/g/catalog