> Last time I checked, it was possible to update the firmware of Nitrokeys. Which seems to completely defeat the purpose of the device?

Yeah. Precisely my problem with Nitrokey too.

If you can flash it, then so will a bad-guy one day. Not if, but when. You really can't say never anymore these days.

The flashing process is also annoying and fragile, I bought a couple of Nitrokeys for random testing and generally found myself haivng to repeat the process a couple of times before it finally worked.

Also, IIRC not all Nitrokeys have a secure enclave, a bunch just store secrets in software.