Recently I tried to make a minmus mining base between biomes - most of it on a flat Greater Flats, and mining equipment just at the edge extending to high ore lowlands. Of course it failed, and from now I wonder what is the point determining the whole vessel location.
Made a long vessel with only one tank filled up, and tried to transfer fuel at the biomes edge, but it does not change anything. About root part, wonder what happens with something like base, made from many modules each with its own root part