Concerns about BTCR method

[kimdhamilton]

From discussion with @msporny @ChristopherA and @kimdhamilton

Spec should be declarative: as long as you end up with X, doesn't matter how you construct it

The BTCR examples are doing 2 things, which Manu recommends separating.

1. proof of control
2. verifiable claims

For BTCR, why fragments?

• DDOs have almost nothing to do with VC, but can shove VCs into a DDO
• BTCR can build up a datastructure over time, but mechanism is different btw ledgers
• what is the best way to mark "go look for next object"
• we don't have a way to rotate or revoke claim issuer -- see doc for REVOKED