Well, if I'm doing a winter-map, I'd want to call the tiers
Road, Hardpack, Powder, Slush, Drift, Impassable.
If I'm doing a moon map, I'd want to call the tiers
Road, Rock, Sand, Dust, Impassable.
If you're doing something that extensive to a map (say, Gadget "weather" that completely changes the look with fancy shader stuff, which would also have gameplay effects)... well, it's easy, actually.
When a Tooltip comes in for hovering over the terrain and returning that name, it also gives the x,z location. Just get the value of the type at that point, and do a string substitution. IOW, in the SMD, typemap value 2 is "sand"... get the typemap value x,z, if 2 and we're running the "winter" random Weather Scenario, then the tooltip string forwarded to your Tooltip Widget would be "slush" or w/e.
Basically that's not an obstacle, if you're already using a Tooltip Widget of some kind, and I can't imagine somebody trying to build a modern game on this engine not doing so, frankly.
At this point, imho the best mapper approach is simply to keep doing what their doing, and let modders consume or discard the information as they see fit
This, in a nutshell. Once metal is (finally) added to the list... the map's whatever the game designers need it to be, period, and there's no conflict at all with mappers who design primarily with BA in mind. Games can just do their thing, quietly and politely, and mappers don't have to know anything about those "other games".