There are some problem with height levels to think about. It is strange to walk your figures over continuous terrain and they suddenly disappear because they "switch" to the next level. Perfectly fine in architectural maps, but here?
See map as example. When you guys have time, maybe just playtest it, two aliens, two soldier starts. Idea is: there is an island with a crashed ufo. The guys come per boat and neutralize the aliens (ok, it is nowhere near pretty or anything, just for testing height transitions on smooth terrain)
Working on exporting brush height automatically ...