Oh yes, absolutely. In fact Trezor uses two signature algorithms for their firmwares, pre and post quamtum precisely for the case that the post quatum algo ends being unsafe. Unfortunately I don't remember the details. I hope some of them come and comment. ping nostr:npub1lz8xv2dnyryrk4vswkcgf52vqqzruqwuyp53s7pvusx4fef9fh2s7hh86s
Discussion
Yes that's a very good point. I remember now that DJB is a strong advocate for exactly this.
Notice though how in performance critical applications, using even more space and time to do this is going to be ... ouch.
The Trezor Safe 7 boardloader uses a hybrid scheme:
Signed with both SLH-DSA and ECDSA (secp256r1).
The ECDSA signature also signs the SLH-DSA signature.
It is described in more technical details here https://trezor.io/guides/trezor-devices/trezor-safe-7/going-quantum
Sorry there is mistake in article. Will be updated soon.
Bootloader is signed with ed25519 not ecdsa