For Steam Deck OLED support they said it’s ready to the point that “it should be mostly functional”, however there’s at least one major issue left which “has to do with audio crashing when switching to Desktop Mode” and some other issues related to HDR support.
I can’t say for sure if Gnome has anything to do with it, since the DE should be separate from the drivers, but it’s a point worth mentioning just in case. Obviously, there’s differences between both versions, but the devs have tried to make the experience as interchangeable as possible. For example, they include GSConnect by default, so you don’t lose out on KDEConnect functionality.
The controller issue, though, is upstream and affects anyone using the BlueZ package to run Bluetooth.
If anyone was thinking of switching on an OLED Deck, I would wait a bit longer. The recent changes have been great, but just before the update, I was about ready to reimage back to SteamOS due to the frustrating bugs. Still undecided if I will do that, ultimately, and wait for full support.
Fortunately, to its credit, rolling back to a previous working image is trivially easy, so you don’t have to live with specific bugs that get introduced. Benefits of atomic distros.
ETA: if you’re into tinkering and learning a new paradigm for how to work with an immutable OS and layered packages, it works on Desktops as well!