Tiled markers for projections in map charts

Tiled marker shapes on scatter plots are very powerful for aggregating lots of data and showing distributed 'heat maps' of measures.
Currently there is a limitation whereby they can't be used in map charts which use a coordinate reference system. From the docs:
[Only available when the coordinate reference system is set to None, e.g., when markers are displayed on an image background.]
Whilst there are really good data functions to achieve similar results and it can be achieved by using binning functions of the longitude/latitude positions and adjusting the sizing manually, it would be very useful to have this functionality out of the box on maps. Plus the Spotfire aggregation engine tends to be much faster than data functions when working with large data sets.