How should I manage a large number of overlays I have (e.g. ~8000 across the country) noting there will be only a small number in a given view typically as the users typically zoom in a bit. Also noting I want to have direction arrows out from the current user location to the currently "visible" overlays (i.e. on the screen) at a given time? There are Overlays and NOT Annotations keep in mind. Specifically:
Q1 - Should I load up all the overlays into the app upfront? Or should I be manually managing myself which ones need to be displays at the given time and load them, remove them?
If I should load them all up up front then:
Q2 - Does MKMapView actually intelligently render them when visible only? It doesn't seem like this???
Q3 - How do I get a list of currently "visible" overlays from my MapView to create the direction pointers from the current user location? I can't see any function in Mapview to allow this? So does this imply I would need to manually check through all overlays (i.e. whole 8000) continually to see which ones are visible manually?