(Edit: should specify this is aimed at the phones and qr codes system!) That would absolutely ruin the atmosphere for me though, the character of a bar is the bustle and people standing around as well as the chatter you get sometimes.
Removing all that and just having people tap away at their phones while the bar staff silently make drinks, then people walking to a box to grab theirs honestly sounds uninviting.
Nice concept on paper but it'd ruin a bar for me.
I know KDE has a calendar, not sure how well it'd work for your use case but it's there!