[tater]

Bearcat, I mean maps that started from NOTHING, not retextures of existing maps.

Some of the maps alluded to are not based AT ALL on any stock maps. They were created from whole cloth (and space shuttle radar topography mission data).

they are not stretching existing maps, they are not redecorating existing maps, they are... NEW MAPS.

The only stuff reused are textures/objects since there is already a substantial library of decent textures and objects. Reusing stock textures (most all the stock maps, do, too) is desirable since it increases compatibility for anyone who wishes minimal changes. You can absolutely ONLY load new maps as mods, for example.