hey, @iangilman! I have been rewriting sources and noticed one thing. When we load a single tile(as they are loaded separately) we call the UpdateViewport() method, where we iterate through all tiles with different url, in a single tile URL, and look if they are cached. Maybe it could have been more convenient, toggling single UpdateTile method, on a downloaded tile, because, as I suppose, we have a great performance loss on that big loop. Correct me, if i'm wrong. Thanks!