I have used https://github.com/iann0036/iamlive with great success in the past. On high level, the approach you are describing is iamlive on steroids and UX improved.
Wow. That seems to be a succession / resurrection of 2015-2016 projekt I was involved with Norwegian Consumer Council forbrukerrådet and some of major groceries chains(Coop, Rema, NG..)
The moment I left we were receiving soft real-time Pos log data (anonymized) and we’re building some consumer groceries basket stats.