I think it makes sense for relays to either focus on doing the main relay job of taking and serving everybody's posts and filtering spam, OR to focus on providing INBOX services to users.  The latter would accept giftwraps and any other events tagging you, and would probably constrain how much space they should be allowed to take (just like an email provider).

Certainly a relay could offer both, but it might be better for relays to specialize.

What we are missing though are relays specializing in being INBOX (read) relays. Which is why I keep thinking about writing a relay --- but that's nuts right? I mean we have tons of developers writing tons of projects, I shouldn't spread myself so thin.  But I'd really love to pass on the tech that I was going to use to build it to some enterprising programmer.