PPR information is noted in the "Admin information" section, under "Opening hours", besides in AIP.For planning purpose I would love if the "Find a destination" would allow to filter for airports where PPR is not listed. Maybe associated with a depiction (text or color) similar to Ratings and landingfees, if PPR is required always or only outside opening hours (O/T).
It would make it easier to get an overview, before reading the details and checking AIP.
The "Find destination" is very useful for fuel, ratings, fee and facilities, adding the PPR search capability would be a great addition in my mind.