If there was no obsession with registrations, it wouldn't have been a problem at all.
For the menu no app is needed, the places I go always open a web page menu(provided by a service specialising in this particular niche).
The payment could be completed through things like Apple Pay, per table basis. So you scan a QR code, it instantly opens a session for you and you can start ordering things and once you are done you close the session by paying through some payment processor.
Also, the technology to open apps with temporary sessions without installing the app exist both on iOS and Android but for some reason it never got popular.
I think that's the custom in the vast majority of restaurants, but I don't think it's incompatible with the system described. It doesn't stream payments in real time, does it?
For the menu no app is needed, the places I go always open a web page menu(provided by a service specialising in this particular niche).
The payment could be completed through things like Apple Pay, per table basis. So you scan a QR code, it instantly opens a session for you and you can start ordering things and once you are done you close the session by paying through some payment processor.
Also, the technology to open apps with temporary sessions without installing the app exist both on iOS and Android but for some reason it never got popular.