Currently, if you have the setting to put every Factory on the same surface, all factories regardless of force are on the same surface, which in a PVP scenario could create some interesting dynamics with being able to targer the insides of another forces factories with something like artillery shells. Splitting up the factories on a per force basis would protect the insides of the factories from such an attack to a degree. Yes, adding this in would create migration issues similar to adding this mod in after the original factorissimo mod, if a clean migration path can't be found, then perhaps a PVP fork would be something to consider. Obviously using the per factory surfaces also solves the issue as well. Just something to consider.