Actually I believe it was Spyder who discussed this particular point and fairly recently. FWIW, it is my habit to tape from the OB. It is also to good to remember that an OB is as well an internal. lj
An OB accompanied by an IBGS after a point 3 in an up traverse is a very reliable SOC on a traverse level for me. (i.e I anticipate a down traverse in that case) FWIW.