This is the usual misconception about ghost ball. The ghost ball is located at whatever position is needed for the shot, not necessarily on the straight-in OB/pocket line.
pj
chgo
Yes, as I wrote one needs to find a spot that hit with the CB will send the OB center pocket, whatever method. If you use GB you line it up to whatever part of the pocket is necessary for the OB to enter center pocket after its hit with the CB.