About the plugins you linked: Don’t both offer the same feature: link github issues to the forum?
The other way round would be indeed interesting! But I agree with Jason, that this could lead to spam as most issues posted here are not (or not only) nextcloud issues.
I personally always try to find the related issues on both and link them wise versa where I deal with one. Of course not all do that, nor do all forum users know about github I guess . Could be in case also a job for the moderators to add links and in case combine/clean identical issue threads.
Ok, so that’s the right one. But I’m far to afraid to break stuff (well, more the resulting being yelled at by @LukasReschke) to be willing to even try to install it, sorry. Have to let Lukas help out with this…