I saw some things so I wanted to add in my stuff on video.
Its' a tad long though and..
This was interesting. Thanks.
What I took from this is that there are some really significant differences between a standstill slash one-step throw and an X-step. They may be more different than alike.
Overthrow Disc Golf had a recent segment on upshots saying they are very different from a drive, and at the Stokely clinic I attended he said he thought eventually all the pros would have two different backhand throws, one for power drives and one for others.
I'm still in the throw-everything-from-standstill stage.