I wish I had handled the "proof of liabilities" question better.

I knew about proofimint, which was one of the Fedi hackathon winners from last year, and the general direction of counting minted/burned ecash. But I couldn't remember the name of proofimint, and in general didn't want to say something incorrect about the technical limitations of how Chaumian mints evidence liabilities.

This primer by Calle goes into good detail on Chaumian proof-of-liabilities:

https://twitter.com/LynAldenContact/status/1747048523600707925