Second Ps5 Just for Save Files / Modded

Hey, I've seen a lot of websites and YouTubers selling modded and/or 100% completed save files. So I was wondering, how difficult is it to set something like that up yourself?

I'm thinking about buying a second PS5 Fat with a low firmware version so I can jailbreak it, but only to create those kinds of save files for my own personal use.

And once I have everything set up, would I need to install every game that I want a save file for on the jailbroken PS5? For example, if I wanted a save for Assassin's Creed IV: Black Flag, would I have to install that game on the JB PS5 as well?

From what I've read, it seems to be pretty difficult to get newer games running on a jailbroken PS5.

I don't want to Pirate, only some cheats in my save files that i would use on my Ps5 Pro with games that i bought.