Battle Area - what does it do?

[5./JG27.Farber]

Aside from putting a grid on the map, I iniatially thought it might define the rendered area and decide where to render buidlings are trees etc. However I have found no evidence of this and several patches later which may or may not have altered this I still see no evidence.

Be sure to set the last value to 10000 instead of 1000, those tiny squares are annoying.