I downloaded the instructions and it appears that for a 68mm BB, you should use one spacer on the stokers left (sync chain) side and two on the right (drive) side. This matches my memory of an extra spacer on the drive side. Unfortunately the PDF is too large to attach to a forum post. In any case it should be the same as the instructions that you have. A 73 mm BB uses zero spacers on the left side and one on the right so it maintains one additional washer on the right (drive) side.
If needed and possible I would move a spacer to the other side to get the same lateral measurement.