Replying to Look pivot 14 heel adjustment range

Hi all,

I had a set of pivot 14 and the toe piece slide plate mech got busted so I had the toes swapped out for 18s so I didn't get exactly the same issue again with another pair of 14s. This has changed the forward pressure, anyone know how to tell you are in the safe maximum extension of the adjustment range? I had one cuff of etched lines before, now am at the outer extended end of the 2nd ring of etched lines.... I heard tell that there is a 3rd ring on the arms and that is the max extended range for safe use (and also that you can keep turning till they literally come undone). Does anyone have the knowledge of whether the maximum length safe range is the top (most extended) or bottom of the 3rd ring of etched lines. If this makes sense.

B