I also agree and have been talking with @eturnerx about repurposing FOSSbot for a task like this. In their own words it's a "coarse parameter search" which could (and perhaps should) then be refined by humanz.
I love your idea of an "Underrated" tab on Steemit. We've been talking about this kind of thing to (and me elsewhere I suggested you should a custom filter tab) and it should be taken off the blockchain and UI middle processing.
In a few weeks I will post some ai notebooks that use Steem Data for such a similarity analysis. Just out on vacation for some time so it has to wait a little
Looking forward to it, followed 😊