Well ideally when you go along to your next appointment, a good advocate ironically would be another parent whose child has CAH and whom has been on this regime a while and doing well.

It is probably going to be a while before any Doctor who is reluctant to change from the conventional way of dosing see the benefits.  The only thing that you can do is use the time between now and January educating yourself about it all and gathering abstracts and studies to support your point of view.  I think most good Doctors once seeing that you are determined, would make allowances after studying those.