I think this is a bit radical claim, but I would avoid any synchronous chatting platform for F/OSS development including IRC, it is simply not worth its cost.

I think this is a bit radical claim, but I would avoid any synchronous chatting platform for F/OSS development including IRC, it is simply not worth its cost. IRC is commonly quoted to support the asynchronous mode of chatting but it is somewhat misleading: asynchronocity is embedded to the IRC community and not the protocol. If IRC the protocol were actually asynchronous we would have, for example, a better story for mobile clients by now. Probably Zulip is better at the asynchronous mode, I'm yet to try out. Now it is another story when you consider your clueless end users, who see proprietary platforms as a norm and actively seek the synchronocity ("anybody out there?"). I think you should be in (some of) those platforms in that case, because it is practically more important to help your users. Or maybe not, if you know your users don't like synchronous chat or proprietary platforms anyway. Throughout my history of using IRC, it was most useful as a synchronous Q&A channel and an asynchronous community bookkeeper, both irrelevant to the IRC protocol itself. I don't see why we should pursue IRC further. (Now it is funny that I still operate my own IRC network!)