Question about Seedsigner

I think I've decided for Seedsigner as my cold storage solution. The idea of a stateless bitcoin computer speaks a lot to me. In fact it's the one solution that makes sense to me, because you truly don't need to trust anyone, especially not manufacturers of hardware devices.

So here's my specific question: 12 words or 24 words?

I’m in Germany and I’d like to order off-the-shelf steel plates, called SteelQR. The handy credit-card-sized plates are only available for 12 words, but the 12 word QR code is only compatible with Seedsigner, not with other devices or software. Basically I'm insecure about locking myself out if I lose or brick the device. Not as in losing my funds, because I'm supposed to have the seed phrase permanently stored in a secure location for backup, but as in losing direct access without traveling to the seed phrase’s location, and I don't want to be required to obtain another device in cases of emergency.

Remembering either 12 or 24 words off the top of my hat is not gonna happen; I know that. I’ve looked into mnemonic devices; I don't have the capacity for that.

Basically I find myself in a similar situation that made me want to upgrade from Electrum in the first place; to not be bound to any one particular solution in case the implementation disappears.

Am I really locking myself into using Seedsigner when I only have the 12-word QR code available with the seed backup in another safe but currently inaccessible location?