Fedora Chat: Matrix ⮀ IRC Interaction issues

We’re getting ready to launch our new matrix-based Fedora Chat service. This service is bridged to our traditional IRC communications channels on libera.chat. As part of this launch, we’re looking at how other communities have done this. GNOME in particular has a lot of useful experience to share, and I found their tracking issue Ease interactions between IRC and Matrix users useful. In addition to that being a direct resource to look at, I thought it’d be good to have our own such list. So, this post will be that. We can keep this top post edited with a list of known issues with workaround, and discuss in replies.