Supposedly, the biggest change was simply removing the launcher. Because in order to be steam deck verified, it can’t have the intermediary launcher that interrupts the game booting.

But removing that apparently broke a lot of other things for a lot of people. Supposedly, doing a fresh install helps. Apparently the update fucks some stuff, but a completely fresh install will be buttery smooth. At least, that’s the scuttlebutt. But that doesn’t include mods which have been broken, (and many which aren’t being actively updated anymore, because why bother updating a mod for a game that hasn’t had an update in years?)