meanwhile, it is very unclear that any sidechannel attack on a libolm based client is practical over the network (which is why we didn’t fix this years ago).

Wow... Uh, that's certainly a thing for a developer to let slip out, huh?

One thing I don't get about Signal/Telegram/etc is that they claim to be secure and private... Yet also require you to prove your identity via a phone number? I don't really get it.

That would be a massive deal breaker to some people I want to push off Discord and is one of the reasons I haven't tried Signal yet, but have tried Matrix.