Hi Jens,
welcome to the forum. Always good to see people interested in making maps.
I feel HexDraw is the wrong horse.
As developers, we* have switched from HexDraw to the combination of a GIS tool and an in-house map renderer to create maps.
For Southern Storm, we are using a larger palette of hex colors and hex side colors to model terrain in more detail and variety; we do not have matching HexDraw styles/art available.
Southern Storm also does no longer support manually changing hex values; all input (and changes) need to come as part of the terrain bitmap being scanned.
The GIS tool (called QGis, it is free and open-source) is more powerful, and allows quicker creation of maps, especially when based on real-world terrain. See this
forum thread for a tutorial to create a Red Storm map using QGis.
It also supports quick changes in styling, so you can quickly retarget a map designed for Red Storm to be used in Southern Storm.
QGis does have a steep learning curve though. And doesn't automatically give you a pretty map to present during the game (although you could use one of the many OpenStreetMap/satellite overlays it is able to place on top of the map).
We use an in-house render tool to create the pretty maps.
Hope this helps. Let me know if you have further questions.
(*: mostly me doing the maps)
William