I'm still not sure I'm quite following you, partly because forests, mountains, and land-mass styles are all terrain parameters to me. Also, the only way I've thought of "default" is what the map options are for a freshly-installed game. What you typed above sorta makes me think of those big-flat LEGO foundation pieces. I'm not a coder, so it all looks like 'map' to me when I get a game started.
Could it be that you want something like a slider for Devastation, with one pole generating maps with no habitable land on turn 0 and the other eliminating the imbuing-lands thing from the game?
I haven't played tons of games, but 0.264 seems to have a lot of what looks like ecosystem variety to me. The swamps are now distinctly different from the mysterious color-change around some (water?) shards, and there are deserts. I'm pretty sure that tundra is at least being considered for the mix as well, and it would be nice to see a couple of forest types (tropical, boreal) rather than just generic forest.
Anywho, I'm not trying to be annoying, just persistently thick at the worst...