When I upgraded my SSD in my old 64gb model to just a 256gb, I had to reinstall all my games from scratch, including D4. Nothing would work otherwise that I had on my old SD card. After that I had no problems. When I get back from a concert this evening I can look and see what version of proton my D4 is running so that I can say with certainty that it is working and let you know
I highly recommend one. And it's currently on sale! I originally got the base 64gb one but then spent 18$ on a 256gb nvme drive and upgraded it. Cheaper than buying the 256gb direct.
It's way more than just an emulator for me too. I've been playing a ton of triple a games like diablo 4 on it, I even used it as a desktop replacement for a bit while I was moving and it did fantastic
I mainly used it to play emulated ps1 titles and a ton of Jrpgs. Star ocean 1 remake and star ocean 2, tales of phantasia, castlevania SOTN, xenigears, the list goes on. Even had a really good snes emulate I was able to sneak on there somehow and was a great portable snes machine.....just like my steam deck is now. How things change yet stay the same.
The obvious answer, for true fear, is to either run TempleOS or Red Star