Year ten is very different from ten year old, but that’s not typically how we say it in the states so that might have been the confusion. We usually say tenth grade, or sophomore.
The only problem I see with dropping the yoyo from a machine is that most of the benefit of a string centering bearing is gained from I staying centered during a trick.
I’m not trying to dissuade you, I’m just saying you might have to be clever about what you test for and how.