I meant actually getting rid of ports, so the recipient wouldn't need to bother.

But I guess one could always just bake it into the DNS record, so perhaps not a big issue in practice.

Ah I get what you mean now. For the most part I just don't care about similar things running on the same port, because I've got many thousands of addresses I could just choose to listen to. I can have tons of different things listening on :80 or :443 or whatever on IPv6.