Most teams take the same sail and test it on different masts, if the diamonds (spreader rake and diamond tension) are the same (hence no longer a variable) and the sail sets up differently then we further investigate the mast.

Measurements are taken with a fixed camera rig mounted on the top of the mast, offsets are measured and the differences are measured.

We also measure the mast in use with load cells attached to the diamonds, mast step, shrouds and forestay. This is recorded and matched to the photos taken at the time.

Interestingly some masts, Such as yours, are stiff in the static tests and soft in the dynamic situations...

Small variations can be tuned out but its hard to get really confident with one mast then change to another. they behave differently accross the wind range. Not so much of a problem if you only have one mast though!