"A Badge would place a discreet flyer with a QR code: “Planning to stay and work? Great! A minimum spend of €12 every three hours keeps the Wi‑Fi flowing.” Staff could simply point to the flyer—no awkward confrontations, no hard feelings."

If I'm a respectful customer with a laptop and I sit down and some staff comes and does this, I would simply leave. People will go to cafés where they feel welcome.