If think they’re missing the ball a bit with “no algorithms”. Even intersecting the recommendations of two humans has to be done by an algorithm. “Refinement” is also a weird term for transparent recommendations.
But I like the idea of "Intersection, not union". Readup's AOTD algorithm is doing exactly that: intersecting everyone's (verified!) reading activity. Which is importantly different from having only experts run the show.
Curious to look at some experts' recommendations on this app! (with Readup :) ).