I joined the 9 files with GMapTool, split the gmapsupp.img and made a gmap-installation with JaVaWaMapconverter.
Everything went well in Basecamp. (In GMapTool I have a link to cgpsmaper 98c routable)
In Basecamp I see the whole France Light map. It's good tho have a total view of that map in Basecamp (off corse You can use Pro-version).
Only the routing don't work well on the border of two original maps. On the map layout You don't see any difference, until You zoom in to 20m. Then You see a breakpoint in the road. Thats where routing goes wrong.
So for having a total view of the map it's good.
For routing just use the original *.img in Basecamp, You can switch between these maps to make a route. See also post #5.