When building *native* native apps you generally have the ability to add in custom descriptions for things like location use or camera use, etc.

I'm not overly au fait with the Android side of things as I have been fussing on iOS for now, but I did manage to find a way to do what I want and keep the Expo builds - in the ios key in app.json there's the infoPlist key (https://docs.expo.io/versions/latest/guides/configuration.html#infoplist) where you just add arbitrary Info.plist stuff. So I managed to do what I wanted there. However, it would be arguably more useful to be able to do this in a more officially supported way, and, if Android also supports descriptions for these features, make it more cross-platform, like the Permissions API itself.