The Mastodon founder, Eugen Rochko, has just announced that "We’ve moved our internal communications from Discord to Zulip at Mastodon".
https://mastodon.social/@Gargron/116041405748460511
Zulip is probably more focused toward work than TTRPGs, but it can't hurt to try it. (I haven't tried it personally, yet.) It is self-hostable.
What's much easier than dual boot on the same hard drive, see if you can install a second hard drive (not too expensive if you buy used), so that Windows can have its own little quarantine cell.