The clamped flat bars are more accurate than the cam lock. Clamp to the side flats. Point them straight up, measure between the with a ruler, and a square.
The crank wheel teeth are 6 degrees. If you are moving your cam timing, keep that crank wheel in mind, not 5 or 6 at the cam. That is twice crank degrees.
All of the race miata timing , retards the intake 5 degrees and picks up 3hp at 6500. I doubt that these engine are much different. The only reason tto advance it at all is for a little more low end. HTH.
I took pics today actually.