Official comment

Maps Made Easy is essentially a raster making machine. All generated GeoTiff outputs are capable of being loaded in to GIS or CAD software as a georeferenced raster layer.
The baselayer map is the map that is there in the background by default. We would use Google Maps but it is extraordinarily expensive to be used in a private setting so we use Mapbox as a basemap tile provider.
The accuracy of the volume measurement is very heavily driven by the quality of the elevation layer and 3D model. More overlap creates more accurate results. We have been told by a lot of our users that they are experiencing volumes within 1% of other measurement techniques. We have a couple of cases where users have gotten within .5% of RTK verified stockpile measurements.
Here is a gdalinfo snapshot of one of our GeoTiffs:
Coordinate System is:
GEOGCS["WGS 84",
DATUM["WGS_1984",
SPHEROID["WGS 84",6378137,298.257223563,
AUTHORITY["EPSG","7030"]],
AUTHORITY["EPSG","6326"]],
PRIMEM["Greenwich",0],
UNIT["degree",0.0174532925199433],
AUTHORITY["EPSG","4326"]]