Hello,
Most probably it would be better to ask it in flathub’s forum, but how to download updates only then rpm fusion and flathub nvidia drivers are both ready. I can use some programs if flathub is late. 
RPMFusion is a tricky one. It’s not technically a part of Fedora, so you’re unlikely to get much support on the Fedora Discussion site, but that might be one place to start (at least a place to get more targeted support, as both topics you mention here are independent of the desktop environment in use).