He didn't say the safe place wasn't a safe. Likely it was (see 3rd pg)
A pendrive is just a small USB storage device.
Fairly reasonable plan, overall. But needed a backup. Which can be difficult if you only have one safe place.
Discussion
Yeah I think USB key is basically just as good, maybe better if encrypted, as a paper seed. He should have had the keys on a hardware signer and the USB as the backup imo
I didnβt see the safe part. If he put it in the safe, itβd still be there. Probably fake. Heβs been stacking for years and has 24 karma? π