Suddenly occurred to me: I predict algorithmic and automated bank (mint) runs, or rather the threat of such, are in the near future. It'll be a way to keep the mints honest.

Multi-mint wallets would be able to communicate with others to manage mint trustworthiness, and a mint that violates the contract can spread that info, and others would verify the discrepancy by testing the mint in question and either gossip or stop the rumor. A rumor verification protocol to filter a gossip protocol.