as I thought about it more today: once I have an ecash token, I can email it to someone else, who can print it and hand it to someone else, etc. the mint can't be aware of any of that activity and can only check validity of a token on redemption. Hence the "true bearer asset" bit.

maybe there is some way for a wallet to ask the mint to give it back copies of tokens that it was known to have... havent looked into that.