That architecture is really nice for signing. But for Cashu mints, since putting a mint in a Nitro enclave can't prevent rugging then doing so has to be useful for something else in order to bother (and pay) to do it, and that something else for me is mint insurance. And the smart contract facilitates the business end of the insurance side.

Although maybe there's some other benefit to putting a mint in a cloud enclave that exists despite the fact that token holders can still be rugged, I just haven't been able to think of it.