The inside of the cue is on the line with the cte line, after the pivot it is exactly dead center cue ball to somewhere on the object ball, right? im not sure im getting you, Dave?
Just because the tip is at center ball doesn't mean the cue is on the CTEL - it's not. Otherwise it'd be a parallel shift as opposed to a pivot. In order to pocket balls, the butt is NOT on the CTEL even if the tip is. The cue is on a different line altogether. It might seem like it, but it's not.
Dave