Ok, so I made I new definitions.txt file for the Artifex map editor including the above terrain types, made a map with it with some of those terrain types, made a single player campaign file, loaded up the game and ran that campaign and....
it works. All the blachole hexes have unique icons, shipping lane and dustcloud hexes look like normal space though.
The advantage however, is that we now have another terrain type from which to trigger missions from, as missions can be coded to trigger in dustcloud hexes.
The complete list of terrain types that a mission can be specifically set to trigger are as follows:
kAsteroidHex
kNebulaHex
kBlackHoleHex
kShippingLaneHex
kDustCloudsHex
kEmptySpaceHex
kAnyTerrainHex
kBaseStationHex
kBattleStationHex
kStarbaseHex
kBaseWeaponsPlatformHex
kBaseListeningPostHex
kAnyBaseHex
kHomeworldHex
kCoreworldHex
kAsteroidBaseHex
kColonyHex
kAnyPlanetHex
As you can see, the only one on this list which hadn't made sense up until now were the dustcloud hexes.