Hi See Michel,
Good question. I don't really have any experience with GIS systems, I come mostly from working with game engines.
The output files are named by QMID, which is the internal FS structure for translating Lat-Lon information into a quadtree(with 6 root nodes) for the scene graph. If you're not familiar with it, you can read more on it here:
https://msdn.microsoft.com/en-us/library/cc707102.aspx?f=255&MSPPError=-2147217396 and here:
http://www.fsdeveloper.com/wiki/index.php?title=BGL_File_Format#TRQ1_Record .
By visualizing this grid, you can imagine that a linear translation to QMID is possible. For example, QMID Level 7 ranges from U=[0,95] in Longitude and V=[0,63] in Latitude. The Lat Lon of the top left pixel could be computed from the following proportions:
double lon = ((double)U * 360 / Umax) - 180;
double lat = ((double)-V* 180 / Vmax) + 90;
The tiles all stretch a full cell with 256 pixels (elevation is a little special in that it has a 257x257 "skirt" for adjacent chunks, so ignoring first row and column), so the Lat-Lon extent of the cell could be derived pretty easily from that. If this checks out I could pretty easily automate this calculation as part of the output in the future.
If you run with a BIN output instead of BMP, I believe it would output what you would call a Band-Interleaved-Pixel raw format (BIP). It would be a signed 16 bit, single channel for Elevations. As above, for elevations they are 257x257 files, ignore the first row and column to arrive at a 256x256 tile. I could automate this as well.
Hope that helps,
Sean