For me, that X45 CG is looking to be 71mm from the tail cone end, with the FOD screen on. Right where the 2nd empty mounting hole (from the front) is.
I know it sounds kinda weird that adding the FOD seems to be going the opposite way of what Gaspar posted w/o FOD, I double checked twice more to be sure before posting this. Hope this helps. Mine does not have the latest elbow connector, is the straight connector version.