I've done some chrono testing, and I can't figure out what all the fuss is about. Basically messing with draw lengths of +/- and inch and playing with bow length does nothing more than add or subtract a few fps. Its kind of negligible in my opinion. I would rather hit the spot than beat myself up over the small stuff. I could just shoot a recurve or a R/D bow if I wanted to squeeze every last bit of velocity out of an arrow.
From a bowyer point of view, or a true expert shooter, these things may be of more importance I would guess and maybe worth pursuing. I have noticed some Hill style bows of various builders outperform others, but all the good ones are pretty darn close. I haven't shot them all by any means. Part of the beauty of longbows is that the limbs aren't moving like a curve, and so small changes in draw length don't mean much for arrow flight variability. That said, if I could shoot a 5# lighter bow with the same arrow energy because the design was excellent and fit was good, I'd go for it!