I've just got a bit of anecdotal experience to add.
Recently the performance has been really inconsistent. It happens during solo missions and squad missions, but I'd say exacerbated with a squad. When more AI gets in the map, especially steel path, it ends up getting stuttery with a high framerate, dropping from 144 to 100-120 but feeling much worse because of the bad frametime. I've turned off character shadows and local reflections to try to combat it but the stuttery frame drops happen.
The game is just not running well right now, there's really no amount of computer you can throw at it at this point to improve it, unless you're lucky.
Gigabyte Aorus Z590 Elite
Intel i9-10900k @ 5GHz core, 4.8GHz ring - Temps never over 50C with push/pull 280mm rad
EVGA RTX 3080 FTW3 Ultra Hybrid - Temps never over 55C with 240mm rad
G.Skill TridentZ 2x16GB DDR4 3200MHz 14-14-14-34
Running on 2560x1440 144z capped framerate to 144 which improves stability somewhat