Would also be interesting to see a graph of how much each playtester switches racquets in your playtester profiles list too.
Working at TW must make you a bit addicted to trying and switching to all the new stuff if you're a racquetholic ;-)
We have not tried proportional stringing, or Sergetti stringing. The only change of tension we do while stringing, are some of the common practices. For example, pulling tighter on the last strings before tying off, or a few pound difference between the mains and crosses of a hybrid.