You’ll be totally fine doing this. If you’re picking up they won’t need the student ID because you’ll have already verified status through Unidays. Also, who’s to say you’re not a mature student or educator yourself?
I’ve done the same with my educator discount and I didn’t get asked for my staff card or anything when I picked up. That was a year ago though but I doubt they’ll care now either.
So order for pick up using his unidays..... collect in store with order number and pay how I want on collection. No association of the device with my son or his Edu at all, including AC+ ?