This is a generic feature to allow retrieving a "larger" tile and splitting it up.
There's a number of specific cases where this maneuver is useful - especially in vector tiles where it makes sense for a provider not to serve up redundant tiles once you're at full resolution. The MBTiles provider in #107 for instance doesn't make sense to ship without adding that in.
But it would be good to have generically for both raster and vector - if nothing else it can decrease the number of calls made externally by getting 512 tiles from every other zoom level and serving up 256 tiles.
This is a generic feature to allow retrieving a "larger" tile and splitting it up.
There's a number of specific cases where this maneuver is useful - especially in vector tiles where it makes sense for a provider not to serve up redundant tiles once you're at full resolution. The MBTiles provider in #107 for instance doesn't make sense to ship without adding that in.
But it would be good to have generically for both raster and vector - if nothing else it can decrease the number of calls made externally by getting 512 tiles from every other zoom level and serving up 256 tiles.