Apps built with a toolkit which ships its own filepicker will immediately attempt to enumerate directories in `/`, `/home`, and probably a few other places.

Apps with a config file will often try to read `~/.config/myapp` and also `~/.myapp/config` and maybe one or two other places.

How many permission prompts will users tolerate?

I'm assuming that the config scenario can be re-routed so the app thinks its opening that file but instead gets routed to different ones transparently.

If the file picker enumerates N different directories immediately (which aren't the active one) that causes a problem yes. I guess allowing enumeration access _anywhere_ (but not file read access) isn't a necessarily a problem.