It's funny that you mention the breaking of keys using outdated algorithms; I booted up my Standard Notes app and there's an "Encryption Upgrade Available" noti

It's funny that you mention the breaking of keys using outdated algorithms; I booted up my Standard Notes app and there's an "Encryption Upgrade Available" notice at the bottom which has you enter your password to locally regenerate your keys. I could imagine something similar working here, and perhaps let your progeny have access to your credentials postmortem.