All AMD sponsored titles so far had way worse RT than Nvidia sponsored titles, because they can't go all out because it'll make their cards look bad, and Nvidia are simply more competent with RT. Yes, AMD offered close support with the RT, they even did a video about their great cooperation. The shadows in this game don't seem like a bug, just very low res. Look at the last Far Cry and how AMD gimped the RT. While even in Cyberpunk, the RT was very good. Looked great and thanks to DLSS, ran good as well. I had a great experience on PC at launch.
Dunno if we can blame AMD for the compilation stutters. But I'd imagine Nvidia going nuts if one of their sponsored games would run like this. Not saying Nvidia has a perfect track record with their sponsoring, we all remember Arkham Knight.
In Callisto, RT shadows introduce a ton of shimmering and noise, if you add FSR at non 4k resolution, it adds another layer of noise. At 1440p, DLSS does a way better job.
That said, the game does look great overall and the RT reflections on high look very very good, top of the class.