Backup of multisig wallet onto steel

At BTC Prague back in June I discovered what I believe is the best (only?) way to back up a bitcoin multisig wallet. It is a backup solution called "SeedHammer": https://seedhammer.com/I talked to one of the founders. These guys have thought just about everything in relation to backing up multisig properly. I decided to order one of their machines - and last week it arrived!

What annoyed me so far with my multisig wallet was the fact that I couldn't find an easy way for my loved ones to restore it if me and my laptop is gone. And I refuse to rely on paper-copies of the descriptor. And since both me and my wife once was locked out for almost 2 weeks from our cloud tool I really don't trust that too. I want things on metal! And no one could backup the descriptor onto steel - until now.

I got my mental model from this guy: https://www.reddit.com/r/Bitcoin/comments/ik0la4/the_best_way_to_backup_a_multisig_wallet/

1. Total self-sovereign (no Casa, Unchained Capital etc).
2. It doesn't rely on electronic devices (no SD cards, thumb drives or cloud backup).
3. The minimal amount of keys (in my case 3-of-5) can recover.

With other words: any 3-of-5 shares should be able to recover the wallet. SeedHammer accomplish this.The concept is that you buy a "steel printer" from them or another supplier - its an off the shelf industrial machine which, according to the creator, was invented to hammer serial numbers into forklifts.

I googled the machine via reverse image search - it is this one I believe: https://www.alibaba.com/product-detail/3020-400w-beauty-equipment-electronics-jewelry_62461522357.html

The machine only has a USB connector and is otherwise completely air gapped. The machine is controlled by an air gapped raspberry pi zero (same model as a seedsigner, which I already had one of) and they reportedly developed the controller software themselves. I don't know much about code, but their repo is open source.

So far I am impressed. The backup was easy and the quality of the plates are very good and it gives me tremendous peace of mind that I know 3 out of my 5 plates is enough to restore my wallet. It is easy for me to instruct my wife and children in what to do in case something happens to me.

I know there is quite some discussion about singlesig vs multisig. But I just want to let everyone know that multisig in this way at least seems to do the trick for me.

The plates are stainless steel - I would have preferred titanium. I have written to their twitter profile but no answer yet.

One other downside is the time - it took me most of a whole day to hammer 5 plates (front and back). I know it is a low price to pay for sovereign peace of mind - and not something you do every day - but I feel it could be optimized somehow.