Correct... to a certain degree. The first dose is the most important, you can still get higher after that, but it will be a lot tweakier and full of side effects because your serotonin is released the most by the first dose, and anything after that is going to release more dopamine and norepinephrine, which you don't want.
I would probably take one and a little less than half of another. Don't pay attention to that KG/MG shit, that could lead you to dose unnecessarily high. No one should need more than 150mg of MDMA at once, and even that's a bit too much..