> as anonymous digital currency and use cryptographic penalties like slashing

Or make it so that tokens cannot be tested except by spending/burning them, which would significantly reduce (but not eliminate) a black market because it would be hard for any buyers to trust any sellers.

The best outcome here is going to rest on getting people to agree that "good enough" is the best outcome. We want a system that gets the broad social results (e.g. less brain-rot in the kids) without being so impossibly strict and overbuilt that it leads to an even-worse problem (e.g. authoritarian hellhole tools.)