It'd be nice if fuel balancing required the inclusion of a control part, and maybe a smaller part needed on the outside of the tanks to be controlled. That way inclusion of fuel balancing would have a cost in weight and money.

Many people requested that I make this a part-less plug-in, so I did.

I think that after 0.22's release, I will put the mod somewhere higher on the tech tree so that it will not be immediately available. That way, it will have a research cost before you can use it. Hopefully that is an acceptable alternative to a cost in weight and money.