I keep putting off the decision on how to store my private keys remotely in case of disaster, and this looks like a good and very pragmatic solution. Thanks for creating this!

My first reaction was "why not a password-protected zip" and you already linked to a relevant stackexchange question. I think it might be helpful to add a "Why not a password-protected zip/rar/7zip/..." on your page when you have time for it.

Or maybe even explicitly make clear which security goals (confidentiality, integrity, etc.) are satisfied by this. The reason being of course that I would like to show this to colleagues/friends and not having to debate this myself :)