Philosophically yes, I'd like to see a decent way to do inbox. I think how it would play out is: you as an author on an inbox designated relay, make it a paid relay / invite only relay for yourself and/or a small group of just your follow list. Otherwise, accepting all reactions and comments to your notes is spammy and not really what you would want on your designated inbox. Then you would also want your client to connect just to the inbox relay(s) to retrieve inbox related events and a toggle setting for global.
Discussion
I have been testing fully open inbox relays and I don't think they get spammy with tags on my user. But I'd like to see an operator doing some actual research.
I think we have been fairly lucky with reply spam, tho some would likely disagree (if they have been a target of this). Eg. The airdrop bots and others may choose to target specific pubkeys.. Imagine someone wants to attack your inbox, it's trivial for them to reply spam and DM spam you using blaster or any public relay. Even with relays attempting basic rate limiting, I think this is a scenario that will happen (if not happening already). Those that have been targeted, I do see them being driven insane by it..
not quite sure what you're looking for from the ops team, analysis wise.. so here's some fun stats from the nostr21.com public relay.
In the last 30 days:
Kind 4 DMs: 28,236
Kind 13+14 dms: 0
Kind 1984: 1,750
Total events: 1,212,281