A chat site exists for 4chan and altchan users called Gikopoi. It's been in use for over 15 years by users of Western chan and textboard sites. However, there's a small number of fascists who dominate political conversations. No accounts to join, you can even join as anon or with a tripcode.
/leftypol/ should seize control of the narrative and make Gikopoi OUR hangout. We've already done a pretty good job establishing ourselves on Matrix and to a lesser degree Mastodon; Gikopoi should be a much easier win, considering there's only about 20-30 active users in the international server.
https://gikopoipoi.net Once you pick a character and join, you can use the #rula command (just type #rula in chat box with nothing else) to open a list of active rooms you can warp to.
Hail Stalin!