My radio is an old Futaba 9-C with a Hitec 2.4 module, I use my old buddy cord and an old Tower 72 TX as the box. Once in a while I will use an old Hitec 7 TX as the box. Everything works just fine. To completely answer your question it's best to set up the plane and box then try them in the shop to make sure it works for you. It takes about three minutes to do.
The box isn't turned on and in my case doesn't know it has a 2.4 master. I had asked the same question at the field and got too many conflicting answers so decided to try it, works for me!!