Okay I can definitely back up the second claim.
World of Warships, a DirectX only game, runs and loads better on Linux with Proton.
I tested both on SSD and HDD, and in both scenarios the game runs at a higher FPS and loads faster. I legitimately have no idea why.
I originally tested on HDD and guessed that ext4 was just much better with the IO speeds because NTFS would fragment like hell.
But then it also was the same with an SSD and now I'm not sure.