Why do you need your ghost brick to be in the center of some 64x plate?
I dup a build on a 64x64 baseplate, now I need a 32x32 baseplate at the top of the build, so I press B, right click the 32x32 baseplate and boom it auto snaps to the center of the 64x64 plate, then I just gotta shift up and plant. It is a very convenient feature and saves time
Edit: just to be clear this works for any brick, using a 64x64 and 32x32 was just an example