I understand this from a sustainability perspective, but hard to imagine looking back at some asknostr questions and possibly only seeing my OP with no comments anymore as the relays aren’t persisting the useful replies.
I can run a private relay to backup my own notes but it can’t ensure I see related notes 

 Your relay can also backup notes from everybody else you care about. It doesn't need to host only yours. So, if you want to keep your friends messages, just save them :) 

 TIL!