It actually makes things a easier for both blocking and allocating (e.g. VPS hoster) side.
Once the "oh no, we can't afford that many unique allocations" excuse is away, algorithms that enforce quotas for every prefix size at the same time (with no excuses for CGNAT weirdness) stop being too ruthless.
You can distribute your addresses as needed, and I can track successful and failing attempts - at whatever distribution scheme you use. E.g. group your "unverified" or "trial" accounts at a larger prefix size, so they get each other blocked - but not your paying customers.
Once the "oh no, we can't afford that many unique allocations" excuse is away, algorithms that enforce quotas for every prefix size at the same time (with no excuses for CGNAT weirdness) stop being too ruthless.
You can distribute your addresses as needed, and I can track successful and failing attempts - at whatever distribution scheme you use. E.g. group your "unverified" or "trial" accounts at a larger prefix size, so they get each other blocked - but not your paying customers.