If people don't park, and this is more than a minority use case, there probably shouldn't even be parking, because it's probably a massive waste of space.

None of what you've written sounds convenient, it sounds like a massive pain in the arse. If I do have to pay, I'd rather just stick some cash in a machine on the way out, paying for the time I used then and there and making it impossible to be fined or get stuck messing about with an app when something inevitably goes down.

Cashless systems for physical places should honestly be illegal, it would fix a lot of this scammy nonsense.