Indeed Nostr seems to create a tendency in clients to efficiently retrieve notes, which leads to inevitably connect to the most-connected relays. A feedback loop that cannot be altered in any significant way, I suppose. Nonetheless, if users where able to push other's notes to relays it would be great and possibly diminish this centralising tendency.
Could be that adding a new flag to the note standardised format will simply do the job...a flag like the RBF but in this case the flag signals the willingness of the creator to see his/her note pushed also to other relays.
Then adding a simple option like the "boost" button to let users "relay" a note to their relays. Since notes are uniquely identified I guess relays could just trash the copies of one note.
Or this may is already how the "boost" function works, dunno honestly. But adding the flag for the willingness of the user to see his/her note relayed could be nice.
End of the riffing