Is this what you meant by your question? I'm not entirely sure what a 'nostr search engine' means tbh. But maybe I answered correctly lol
Discussion
Does your answer change if you could build a search app from the ground up?
I would still want these features. But I'm sure there's lots of clever features I can't even think of
Also.... Searching for an npub on nostr and having no idea which is the real one Vs all the impersonators. A very nostr problem. Just looked up wavlake for example and found it so hard to find the right one to tag. (It's easier when you are following them tho, on amethyst at least you have a wee symbol on the avatar).