I've been exploring the wrist work a bit more and found something peculiar.
With Wrist Pushups, I have to start at PE1...I have to put very little weight on my wrist or it hurts, the left one in particular. I have to really make sure I am feeling the muscles connect all the way to the palm of my hand, otherwise I get twinging pain.
On the other hand, for Wrist Rocks, and First Knuckle Pushups, I can do them already at SE3...both hands at the same time, on my knees.
The First knuckle pushups I can do on my knees but at the Walk stage.
One thing I noticed is that the long hollow position is actually much harder than the kneeling position, as I can bring more of my weight to bear with the longer extension of the wall hollow compared to the videos of the kneeling positions (in part this is because I do the kneeling ones on my panel mat, and the long hollows on a very hard wall. The athletes in the videos have the padded walls which I'm sure makes these go a bit easier).
Any advice? Are the kneeling positions supposed to be easier than the long hollows?