So the people at Tread Athletics wrote back to me. And they didn't respond with a very good answer at all unfortunately. They just reiterated some basics of what their article we've all read already states, and said to watch this video. And it's the same video about how to determine if your ER or IR dominant :\ I specifically asked them what are some drills, tips and swing thoughts someone could do, IF they are ER or IR dominant and NOTHING. So that was a waste of time.
But the one thing Ben had mentioned in one of his videos was messing around with rear drive leg FOOT starting angles. So meaning, does your rear foot start out 90* parallel to the plate on the rubber? Or slightly open or slightly closed? And it states that usually people that are ER dominant will have better results more often than not (meaning higher velocities on pitches) with a 10-20* closed rear foot. It sets their whole body up to start the pitch in a more closed position, while their body glides down the mound until they plant with a vertical shin.
So translated for us, as disc golfers, that would mean (if your RHBH) you'd turn your left foot more behind you going into the X step, at around 10-20*. As opposed to more neutral left foot angle. So a lot like Simon's X step, where his left foot is turned out quite a bit behind him.
