Block a user for a single channel only

I was wondering about the possibility of a block feature on a channel basis. We all have that one friend who is sane 99% of the time, but if you bring up one specific thing they become unreasonable and you just ignore them, right? In my personal situation it's a guy I've known for like a decade, good guy, but of the server we're both on he constantly comes into a game-specific channel to complain about how he hates the game (which he doesn't even play). No one goes into the channel for the game he likes to do this to him, it's entirely a personality problem and outside of that issue he's totally fine. I do not control the server, and moderators' advice is to just ignore him when he does it, but I'd rather just not have to bother with it in the first place. I don't want to completely block him, however because it's only when you get him talking about that specific thing he's unreasonable. I think this is probably a pretty common situation: the one subject you just don't engage with a friend on because it's not worth arguing with them. You don't want to never talk to them again but maybe you just don't want to talk to them about THAT.