I use Kinoite currently and at first I had some trouble finding out how to do certain things in rpm-ostree, when a lot of guides just mention how to do things with DNF. For example I wanted the mesa freeworld drivers, and a few other packages to get codecs working, and had some troubles but managed to figure it out.

With that, my system is essentially set up how I like it, I also have automatic updates for rpm-ostree, and since it only reflects on the next reboot it doesn't affect the current session. That's neat.

I also removed the rpm-ostree backend from Plasma Discover because it was showing as if there was an update but then Discover wouldn't display what the update was. Now I only have Discover for Flatpak apps, works great.

For gaming, Steam as a flatpak I think is the way to go on Kinoite. You avoid some issues you have have when updating the system. It happened to me once at least and so I switched to flatpak version. It works great honestly. And then Lutris from Flathub also seems to work fine, in my case at least.

Nvidia drivers shouldn't be an issue, you have to do some commands on the Terminal, but they're available in the RPM Fusion wiki if I recall correctly.

What I like the most is having the peace of mind of being able to boot to a previous working state if an update causes an issue, and it works out of the box. I could accomplish the same with OpenSUSE but I like Fedora more.