We do already have a thread here talking about moderation over on Steam
https://forums.larian.com/ubbthreads.php?ubb=showflat&Number=868228#Post868228.There's nothing I can directly do (other than pass on concerns to the Larian community management team, which I have done), but given that it's feedback to Larian about community networking opportunities it's a perfectly valid thing to raise in general on these forums.
But I'd suggest we keep it to the thread linked above as that will make it easier to evidence the issue.
And while noone should have to leave a Steam forum because of toxic behaviour, I'll echo virumor and suggest that if it's that bad, it might be worth exploring other options. There's here (if you can cope with the annoying regular poor performance and lagginess - of our forum software that is, not our community members

) or Larian's Discord, to which you can find a link down at the bottom left of their home page.