This.
99% of challenge caches I love. There are a few challenge caches that are problematic - especially ones the owner hasn't actually done themselves, because they are so impossible to do. There are a few I wouldn't do because they don't float my boat. But in the same way, I don't like 1/1 trads because I want to keep my D/T average high, and I'll save the 1/1 for when I'm no longer able to climb trees. So should we ban 1/1's to make room for physically demanding ones for me? Or ban tree-climbs to leave room for disabled friendly? You do the ones you want to do and are capable of safely doing, and ignore the rest. Which brings me to:
No challenge caches that the owner doesn't qual for themselves - will keep the really ridiculous ones down
Consider no challenge caches that require 'all caches in a certain area' - very few cachers like or are capable of 'all' types of caches and there are always a few problematic lost/needs maintenance/CO left the game that make them annoying
Maybe have an attribute to make them more searchable.
But aside from that first point, I can live with the way it was