With the serial numbers and massive storage all they’d need is a pathtracking software and to standardize scanning bills to create records at POS.
Sure there’d be gaps but this’d be automatable, so no more FBI agents in a room copying serial numbers to avoid marking the bills. Then whenever voxel scanning happens a bank worker could scan a whole palette of currency and record its data.
So not 100% but significantly more than previously.
At least where I’m from, people who participate in the flee market do an insane amount of person to person transactions, and a good chunk of them don’t use bank accounts.