I would separate rug pull risk from service failure risk. Cashu is custodial without unilateral exit so with or without enclave, if mint goes down, funds are inaccessible. To me it looks like rug pull...
The biggest issue with Cashu is that even with cloud enclaves (of any kind) there is no escape from central control, and central control means the central controller can rug the token holders. Cashu basically mandates central control no matter where deployed.
If you look at all the ways to build trust in mints that don't rely on cloud enclaves, some are pretty innovative and will get you to the same level of "good enough" as with cloud enclaves. So the only reason to add enclaves if if you can make the leap from "good enough" to "100% sure", otherwise it's just adding cost and latency.
With what you're suggesting I think it maybe could work with Fedimint, but I'm still quite skeptical vis a vis Cashu.
If you look at all the ways to build trust in mints that don't rely on cloud enclaves, some are pretty innovative and will get you to the same level of "good enough" as with cloud enclaves. So the only reason to add enclaves if if you can make the leap from "good enough" to "100% sure", otherwise it's just adding cost and latency.
With what you're suggesting I think it maybe could work with Fedimint, but I'm still quite skeptical vis a vis Cashu.