Possible, just forget backwards compatibility with Boltcard. But that is less secure and less capable as well and you don’t need it for a ground up system
Discussion
yep, don't care about boltcards now. Goals are only:
0. avoid CC fees
1. customers don't need to understand anything, just use tap to pay
2. customers get $-stable, $-denominated prices
3. merchants will take on more infra work wrt PoS and slightly more understanding
Also if you want keyset rotation, you would need to have people tap and use cards every few months.
Otherwise they would expire due to inactivity