I think I've found out why the game kept crashing. After I disabled Fidelity FX in-game (and used RIS in AMD CP) I could play the game with RT on for hours. Psycho's still out of the question, there's something bottlenecking the refresh of the rays hard, or whatever, but all RT effects on, light at medium, seems to work fine. Gotta go down to 900p in order to keep it in 40+ but that's fine. I guess it's mostly placebo but I wanted a RT'ed playthrough and I got it, so now I'm happy. After this I'll put it on the backburner until some healthy expansions release and I get a new PC altogether.
I think if they get Radeon Boost w/ VRS working like they've advertised, and AMD + CDPR work on optimising the code, because frankly the game is a clear-cut Nvidia game and I say that fully understanding the hardware differences between RDNA 2 & Ampere - performance is just too poor, clearly, and as you push the rays and effects you see the performance become bizzare which is unlike even pathtraced titles, or other similarly complex RT'ed titles (Control etc.), then I would say 1080p 45fps is doable. Then perhaps add in FSR and all's okay. For sure there's 20%+ performance available to eek out of the game just raw, from game updates + driver updates alone.