For me it is supported better on Linux than on Windows because my GPU (RX 5700 XT) does not actually have HW raytracing but Mesa has a software fallback for it :-P. If nothing else i was able to see what the fuss was all about[0][1][2].
Though, well, performance was a tiny bit lacking as you can see (i actually had to modify the Quake RTX code to let me use lower resolution scale than the official binary allowed :-P).
Varies from game to game. I know it works in Cyberpunk 2077 but you need to include some special launch parameters. Portal RTX just worked. RTX in Control doesn't work even with config changes.
