VS

In most of my experiences with the Straitline Max Cam which comes on the Q2XL and Q2 they all seem to be 3/4" longer than stated...... Example=My Q2XL has a 27.5" cam but actually draws 28 1/4".
If you can get a cam which puts you within a 1/4" or so of your wingspan measurement you could do some twisting/untwisting to get that 1/4" either way without hurting the timing much.
You are also correct about shorter being better.I personally would rather be 1" too short than 1/2"long.
Good luck and give it time. Good Shootin.