The 2d:4d ratio is related to prenatal androgen exposure, not current testosterone blood concentrations. So for example if we snipped your balls off tomorrow your 2d:4d ratio would remain the same for the rest of your life
A fun experiment to run would be checking out the 2d4d ratio of the lbs in bkk! My bet is on average the ones with big cocks have very masculine ratios. Of course its not a perfect relationship as hormone therapy or androgen deprivation as some lbs engage in can cause some shrinkage/atrophy of the old boy.
