Only a few of the BBs know the algorithm thing for the cap. People are attempting to solve it but don't have enough data points.
The soft cap is applied to the sum of all skills. If you were going for a pure mono-skill player with OD for that SG, you could probably pop OD way beyond prolific (but it would take ages to train at 20+, 6'6" and with the elastic effect). I don't want to talk on subjects I know nothing about, though. I tend to do that very often.