I wanted to follow up on your post with more troubleshooting of my own. I thought KB5033375 had fixed it for me. I played for two days with no crashes but then they came roaring back. Tried a few more things but nothing that was really making sense before I finally tried what I think is the dumbest option ever.

I went into my BIOS and I disabled speed step and hyperthreading. Since I did that I haven't had a single issue with crashing. I need to do some more testing with turning on one and doing more testing but for now I'm leaving them off just so I can play and see if I can get a week without any crashes.

Disabling speed step somewhat makes sense to me because if FFXIV is so prone to OC as everyone says, why wouldn't it also struggle with changing CPU speeds? It's just a theory right now but its one that has let me play again. Good luck on your troubleshooting.