Yeah the aspect of managing such information (extra nip05s, extra lightning addresses) is tricky in terms of functionality. We will see how to implement it.
It's pretty straightforward, you can check it out in my profile JSON or nostr:npub17veg2gt7ja4dnjhs23jyttvpqlde3ajevlxuumxwghnqmgqwuv4q78cc5z's. It looks something like this:

Structure:
content = JSON string with all the fields (including just the first NIP-05 for compatibility)
tags = Array with all the NIP-05s as separate ["nip05", "..."] entries
Other clients only parse content.nip05, so they see one. The ones that support it read the tags, so they see both.
Discussion
would love to see how you could work it in as well as thoughts on use cases