I don't think this is close to NIP-26 at all. With NIP-41 you can keep using whatever client you want, doesn't matter if it has support or not, as long as every now and then you visit the other NIP-41-specific app that you have and let that app update your follow lists for you -- you could even do that only after being prompted by some message that someone posted about someone else having lost their key. It's a single action that takes a few seconds and you don't have to think about it ever again.
NIP-26, on the other hand, would be a lifelong commitment from everybody.