Isn't it going to be confusing though if some instructors do correct him and others don't?
of course it will. that's an obvious problem.
There's going to have to be a consensus among the instructors about what is taught. A meeting perhaps to discuss how training is to go forward?
sure.
Would the chief instructor over rule the others if he felt it was okay to leave him to his boxing style even though the other instructors would prefer to correct him?
yup, he runs the show. But it runs the danger of making the other staff question just what the hell are we teaching here anyway? If the teaching staff isn't versed in boxing technique, and a student is allowed to use boxing technique, I see a whole list of problems arising. Does he get to practice kata with "boxing" punches in it?
Is the training of one person worth risking a rift even a small one among instructors? Perhaps the style comes first?
I say, Nope, and Yup.
To me, the answer to this discussion is really really obvious. You come to me to learn something, you do it like I tell you even if that means changing what you've been doing before. If you don't want to change, then go elsewhere. Why would you come to learn from me if you don't want to do it like I teach it?
You don't have to throw away what you have already learned. Just file it away and keep it separate. On your own time, do that other stuff, no problem. But when you train with me, when you practice the stuff I'm teaching you, you do it the way I tell you and show you.
I really don't see any wiggle room for that.
honestly, if I started trying to do my White Crane like kenpo, and saying, "hey, this is my old habit, and I'm just gonna do it like this...", I'd be laughed right out the door by Sifu and the other students and that would be the end of my white crane training. Why would I waste everyone's time with something like that?