From a technology point of view though, I don't think this is feasible. Coil needs the extension or Puma to be active on a page with a payment pointer, so while you walk around a venue, you'd have to constantly have your phone open and active on a payment pointered web page (which I don't think is realistic from a UX perspective).
The other option would be extremely complicated and resouce intensive: you'd need to become a Web Monetization provider yourself (like Coil), which involves some non-technical hurdles that need to be overcome, mainly getting a corporate relation with one of the wallet providers in the network.
, thanks for the response. That sounds fair enough. I had the same issue and that's why was thinking to specifically try to solve it one way or another, but wasn't sure if it would be possible overall. I was thinking to have a PWA run in the background actively (again not sure if it's possible) or use the BTP token and somehow emulate the webpage through a backend service using the Coil script - and the timing is dicatated by user's location from the phone. In either case, some backend process would be needed to be running on the phone to have a good UX.
I don't think PWAs would work, even with using something like periodicSync. The background processes aren't as active as advertised, you'd be streaming at a much lower rate than the current rate of 36 cents/hour.
The Coil extension is open-source, you could reverse-engineer the tokenization they do to the payment pointer, and make HTTP requests to the Coil BTP endpoint form a server, that should work. It would still be a significant engineering effort, but I think shorter than the alternative.