I'm starting to work on distance searching/views integration on Geofield (see), and it occurred to me that an exposed filter doing geocoded views searches is likely to run into API limits pretty quickly. Under our regular use (saving geocoded data to geofield), this isn't really an issue, but I don't really have a place to store data with views filters. By utilizing Drupal's caching system, this should be relatively easy to do.
Ideally, I think we could make an option that states whether or not we cache a result. The data probably should be segmented to it's own table (cache_geocode?). For fields, it's probably not worth the effort, but makes sense if we need it for other purposes.
One thing that might be an issue is various providers Terms of Service. Looking at Google's for example (https://developers.google.com/maps/terms#section_10_1_3), they forbid caching results unless you're doing it for performance reasons, which I think could be reasonably argued for something like a views filter search.