Some background: 1660 Super, 5600X, 16Gb RAM and a Quest 2 through Link
SteamVR performance overlay is quite handy. It shows you when Oculus turns on ASW in both modes (45FPS ASW On, 45FPS ASW Off, latter being basic timewarp reprojection AFAIK).
What I noticed in both HL:A and Fallout is that even though I am not hitting the 90Hz target, ASW turns on for a second or two then turns off for a second or two. This goes on and on while the 90Hz frametime target is still getting missed very often.
If I force ASW On things get much better, it then only stutters when the composito misses a frame, which AFAIK is because the frame arrives way too late and/or the compositor doesn't have enough time to to its thing.
My question is, why? Why isn't ASW immediately turned on when not hitting frametime targets and stay on while not hitting frametime targets? The whole experience gets ruined because ASW decides that it's not needed when it very much is, resulting in horrid stutter.
It's like the threshold for ASW is incredibly bad. Even when the game is constantly running at around 70FPS the ASW keeps toggling on and off.