I want to speedrun the game but I want to know some things about what it's like to speedrun it on PS5. How different is it from pc? Do i have to modify my game to go to a previous patch of the game or can I just use the most recent one? There my main 2 questions.

You can play on any patch and the Only down side is that you don’t have modified igt and no save organiser

Okay thank you!

PS5 does have a way to store multiple savefiles (on the cloud or on a USB drive? I can't remember), but on PC, you can have thousands of savefiles and we have access to practice tools. The practice/learning experience may be more enjoyable on PC and you also won't be able to disable tutorial pop-ups on console.

In terms of the patches, most runs are optimally performed on current patch (1.06). On PC you may see some people on 1.04, but the difference between 1.04, 1.05 and 1.06 comes down to minor technicalities and they're all considered optimal. Only No Airswim is optimal on old patch (1.02), but the current console WR uses current patch, so it should be no issue. On a side note, it's not possible to downpatch on console, if you wanted to play the old patch, then you would need an original disc copy.

Yes holm you're correct. You can use a USB for save-states for PS4 games on PS5. If it was just a PS5 only game, you can only use a cloud save. Funny enough I think PS4 user interface (XMB) has an advantage of a shortcut button to go the save/load USB settings.

Only issue with USB save-states, is that the game save file limit. Not all areas that you want to practice would exceed the game save file limit of 10. This means you can either spend extra time and have multiple save files on computer then plug your USB into the PC, get the other practice file, put it in your USB, take it out, put into PS5 and play; or you can have multiple USB's.