One nitpick: In my humble opinon, you should switch from Discord chat to Zulip.
It's completely open-source (Apache 2, self-hostable, free full cloud plan for open-source projects) and has an excellent threads-first (called "topics" model): https://zulip.com/why-zulip/
It can run fully in the browser, but it has desktop and mobile clients as well.
It also supports public channels which AFAIK discord doesn't. So you can link to specific messages inside a GitHub issue and anyone who doesn't even have an account can see the relevant messages and context.
Interestingly it's what the Rust language team (and community) uses for comms: https://rust-lang.zulipchat.com
(I'm not affiliated in any way with Zulip btw, I just love the product)