It's quite dispersive, IMO. I should be able to fetch all the profile important stuff with a single REQ: basic metadata, outbox relays, DM relays. > since those are not used by majority of Nostr applications. This make little sense to me, doing a separate REQ to fetch a single piece of data of few bytes seems a waste of resources, and you have also to manage the case where the event is missing.

You can do the multiple kinds you need in just one REQ. I don't get the problem at all.