I think, generally speaking, it would be useful to be able to fetch a list based on its contents.
And have some rudimentary information about each list item without having to fetch each item.
My rudimentary solution is to use a k tag on the list which can be a string of kinds of the items in the list. As you said, this could be a lie. (womp womp)
And then to use markers as a rough way to determine what the item is without fetching it.
But, I’m sure there are more-better solutions and I appreciate the discussion.
Ultimately, I will follow the conventions you and nostr:npub1zuuajd7u3sx8xu92yav9jwxpr839cs0kc3q6t56vd5u9q033xmhsk6c2uc are using because you are blazing the trail with lists. Also, once there is consensus, I’m sure it will make it into #NDK.