- I don’t think so. In any case, Ionic / Capacitor can instantly trigger fullscreen you (they support PWA as well as native WebView apps.)
- If you are creating a client-side app, you shouldn’t really need to set up any kind of server on their device
(unless I misunderstand.)
- As in point 1 - I highly doubt it’s required.
Requiring user-interaction is painful enough for audio contexts - requiring it just to toggle fullscreen would give a questionable user experience.
- Not unless you know you need them (they can be used to handle PWA in offline mode and do some fancy tricks - but you can do quite a lot of that also without diving into service workers.)