I’ve been most curious to do some work around note archival and perhaps curation. Specifically a concept that allows folks to save and publish/read events later regardless of relay retention policies.
My intuition coming into this question was that the cost for relay operators is a function of the number of events currently retained. As such, I wonder if non-relay apps could serve to free the relays up to have a shorter retention period and thus reduce costs while also providing some value to authors (especially of long form notes).