If I’m the one entering the master secret in, then the device is a glorified password manager. The point of an HSM is that nobody, not even the user, can access the secrets. I’m not saying there isn’t a use case for such a device, or that it isn’t possible, only that the security guarantees you get from it are different. The security model you’re describing is the same as someone entering their secret key in the “notes” app in a phone, leaving it in Airplane mode with FDE and wipe after a certain number of incorrect PIN entries. You can call that a “HSM”, but it’s not what I’d consider one.