For relay, They only need HTTP/1.1 as it only deals with one connection. Not multiple contents.
However this problem here has nothing to do with HTTP/2, But rather compression issues that happens on apple devices itself
I think you can support HTTP/2 request easily in by enabling it in Nginx (Assuming using Nginx)
https://www.tecmint.com/enable-http-2-in-nginx/
It will solve connection issue without "hacky way".
I have no problem serving Damus users request in was://nfrelay.app because using Caddy that support HTTP/2 by default. Caddy intercept and reverse proxy the request properly in my case.
Discussion
Does the issue also happened with bostr (JS) or only happened with bostr2? I think we use same Websocket (ws) library in NodeJS so i wonder about it
It seems like the chances of this similar problem happening is also the same as like how bostr2 version 1.0.0 (before fixed by 1.0.1) did. It's also using permessage-deflate.
I would say, Maybe.
Because one thai user that is used to host bot here is using Damus & that also reconnects crazy like the current issue did.