I'm not sure if it'll be helpful to folks, but I posted the Godot PlayerPrefs component I use for my FOSS game #Starscan as a separate repo, today.
It is intentionally the simplest design that met my requirements for a persistent player preferences stash. I use it for things like storing things like window configuration and difficulty settings. It's open ended enough to stash a lot in there, though, like player save data probably.
Feel free to use it or just look and see what it does. It's painfully simple. Hope you enjoy.
A bunch of technomancers in the fediverse. This arcology is for all who wash up upon it's digital shore.