How about regular replaceable events? Are they heavily used?
Discussion
For sure, general bookmark list is replaceable, same for relay list, mute list, group (NIP 29) list and a few more. Kind 0 and 3 act as replaceable although they are not in the replaceable kind range.
one thing that would be very cool is if your relay would keep + return multiple versions of replaceable events, particularly when the filter has a limit > 1
i.e.
kinds: [0], authors: [
if you could return the last three versions of the kind 0 you know of that will be a very good thing
So basically, still treat them like regular events just the order is from lastest to oldest?