Curious to hear your opinion on what are the primary muscles used during hop turns.
Also, are hop turns equivalent to doing plyometrics?
The benefit of plyo box jumps actually comes from the sudden fiber tightening on the landing coming down off the box--not the jump up. The landing of a hop turn is obviously a lot softer--I wouldn't expect a plyo effect.
Technically, you shouldn't jump down from a box jump, you should step down. The point of a box jump is to get the power generation benefit without the landing stress. They are gravity-assisted, if you will.
Unfortunately box jumps often get used as you have described, making them a dangerous option for many, particularly for bigger athletes, and especially with a higher box.
If you want the "plyo effect" (which is really the stretch-reflex from landing to jumping) then a squat jump is a better option.
You might be right that the hop turning isn't entirely plyometric, although I would suggest that's because your boots don't allow your ankles and feet to flex much (depending on the boot/footbed).
As to the original question, I like @markojp's answer: "all of 'em".