I run this one, but valid that you don't know or trust me ;)

Totally hear you on the permissions/access, and there isn't really a workaround:

In order for us to be able to execute your scripts that do powerful things (send notifications, save to local storage, download things, etc.), our extension needs to have those permissions itself.

I started off doing the same as you, having GPT to write scripts for me, and you can go a long way with that. I personally ran into the ceiling and felt I could build out a more robust solution, but it serves your needs well, by all means