Amen...dads, moms...that about sums it up.If a pitching coach doesn't understand IR (forget using the magic words "IR"...but the concept that the forearm pronates at release), then the pitching coach doesn't understand the pitching motion.
A pitching coach:
(1) Must have knowledge of the entire pitching motion
(2) Must be able to identify deficiencies within a student's motion.
(3) Must be able to teach the entire motion.
If a pitching coach doesn't understand IR (again, recognizing that a person in Helena might call it something different than a person in Tokyo), then that coach doesn't fully understand the pitching motion.
The idea that IR is natural is silly...there is nothing natural about softball pitching.