I take my porn quite seriously, and will purchase/watch excellently or interestingly shot porn. It annoys me to no end that this topic draws teenaged giggles on HN.
I suppose you’re limited to what is available in the scene tagging on source sites. I like porn searches that are action-based, videograohy style (I filter out fish eye lenese of POV), colours.
(I’m just having my first coffee of the day and am struggling with coherency.)
A true porn meta search would be AMAZING. The porn industry has a history of not playing fair, which you could take advantage of. Scrape all the pay sites (which is where the quality is) and clip sites Clips4Sale, plus performer databases like Indexx and IAFD. After the initial irritation, I think many porn site owners would actually like it as a source of traffic.