While my experience has been a lot better since I used the Reddit shader fix, I still have occasional stuttering and I have a 3090. Playing offline might be the key to reducing this for me too. I've noticed that playing online introduced more stuttering to my game, but all setups are different.
Stutters are not the only issue of the game, currently.
While super high end users (that includes less than 3% on steam btw) may be fine performance wise besides stutters and asset loads, the fact is that the visuals are saved by art direction, but technically speaking this is very mediocre and yet it cripples the majority of rigs and have frequent frame drops.
The optimization itself + the fact the settings for each option all seem wonky and force "maximum" in a lot of cases, is just pathetic.
It's also super inconsistent.
My game will be at 60 then drop to 54 randomly while nothing is happening, if i turn the camera it's gonna drop frames like hell for 4 seconds, then I respin the camera and it's locked 60.
This is just insane. Each area in the game seems to have different issues so there isn't even a "fix" that sorts it out entirely.