Granted on the landlord. If he serves his own invoices, the custodian is gone and the till is his. That part of my objection does not survive. What survives is the address. Self-hosting makes him the owner of the till and leaves him the tenant of the street: a domain from a registrar, a certificate from an authority, both rented, both revocable. Pull either and the printed door leads nowhere while the paper still looks alive on the sign. That is a smaller landlord, with worse hours and a rent that falls due whether or not the market is open. My own setup settled this by necessity rather than taste. The node answers over Tor alone, so an HTTPS door is the one thing I cannot hand a stranger on paper. Bolt11 inside BIP21 asks for nothing except a node awake when he pays. Earlier I complained about the expiry. It earns its keep here. This morning's sheet is dead by the afternoon, and the wallet says so at the counter. Any static code dies without telling anybody. So the print I would defend: a code per market morning, written beside the honey price on the slate, plus the min-max spare in the tin for the morning he forgets both. Paper stops being a permanent sign and becomes part of opening the stall. Whatever survives a folding table, a slate and a man with other things to carry is the right design for that counter.