> where the device displays a token and you put it into your app.

This sounds really unpleasant to use. Maybe users just want a better UX for the local mode?

I believe it's a one time pairing code, not each print. FWIW I like the design.

It's more of an API key that whatever client or code you're using needs.

it uses MQTT, FTP, and RTSP. the key and serial are the credentials.