I see tools like ExpertFlyer as the typical way travelers search for award space. The general flow, if I'm using it correctly, is to select a route + airline + class (e.g. JFK -> LHR + United + Business) and repeatedly search across multiple dates to find availability.

In this way, it seems like the service indexes based off of the date. When they try to answer the above query, my understanding is that they look at each date and check to see if award space is available for that route. This works pretty well if you know you're going to be traveling on a concrete set of dates, but makes the search exhausting if your dates/locations are flexible and you're just looking for any availability.

Does anyone know if the inverse of this exists? Basically, have a service indexed by route. With this solution, a user would query by route + airline + class, and get back a list of dates. For the flexible traveler, this seems like a much better solution.