If you try that, you will eventually converge on one of two outcomes: the staff will all be using the same app as the guest, for better or worse; or the staff will begin to earnestly recommend that every guest install and use the app, especially when busy or unavailable, because that's how it works now.

Also, remember how HR and accounting work regarding efficiency. If they detect that the human touch is redundant to a fully-functional app, one of them's gotta go.