It seems to be my ecash day. Here is a cool protocol for doing atomic swaps between mints, coordinated over nostr:

Granola is a decentralized exchange layer on top of Cashu. It connects Cashu wallets across mints and coordinates atomic swaps over Nostr. Nostr carries public orders and private coordination; Cashu mints issue and settle the ecash. Granola adds no custodian or additional settlement party.

It's only testnet for now, but it might make moving between mints easier (although it doesn't really help with holding mints accountable like automated bank runs might).