Thank you. I watched all of the videos, except for the whole Bozzio video, because I saw him I concert right before the pandemic, and he is one of my favorite drummers of all time so I am familiar with how he plays. I also own that Steve Smith book/dvd. Anyway, I think what you call “twisting the wrist” is what I call forearm rotation? I certainly don’t see anything wrong with it, afterall it is the basis for the traditional grip stroke. Also for french grip. Of course the difference is that french grip rotates the forearm outwards while trad grip rotates the forearm inwards. In the Dan Weiss example, I see that as kind of an extreme example of American grip, which combines the pivoting of the wrist from german grip and the french rotation of the forearm outward. Again, nothing wrong with that, it is amazing the finesse he is getting with his right hand!
One thing I don’t understand is this “ulnar torque” or “ulnar twist” you mention. As far as I understand it, the ulna cannot rotate or twist, it is locked into the humerus, and can only pivot up and down at the elbow. It is only the crossing of the radius over the ulna that allows our forearm to rotate at all…or am I missing something here?