Yes it really ought punch brail or something?

There is another slot below that reads "archival grade printer".

Correct. But it does allow you to walk-away (with other stuff from the machine) with the keys immediately after generating them, leaving a machine which is little more than a motor and some wires at that point.

So what I typically do is print a warning at the top and bottom of the printout urging the user to transcribe the important parts using archival paper and pen as soon as they can.

Also, if you look at the video, you will see an "Archival Printer" port on the front of the control box because I’m developing a printer that prints the keys (plus QR codes) on metal so they last for decades and perhaps centuries. That may be useful in estate planning where the key may be locked away in a safe, or a lawyers safe, for generations. But transcribing to archival paper and pen is relatively permanent (decades) and is easy and seems to work well (lawyers like it).