I need to figure out a way to phase out old scans - however all my experience with using time weightings in DC have been utter failures. I just tried another right now (a counter that counts every tick of the match) and it didn't help either, although maybe I need to weight it lower than I have right now.
I'm thinking maybe using a limited number of points in the tree, and removing the closest when the limit is reached. Then when I need neighbours for creating a buffer I weight the hits by the time they were logged. This should approximate the way VCS does things.
I don't like the idea of 'doing it the way VCS does it', even if it works, because we don't exactly know why VCS works so well that way either.
Perhaps, for a simple quick method take a sqrt(tree_size) cluster and just use the most recent point. Who knows...