Congratulations!  Great to hear about your new arrival.  Also good to hear that you have found a better way of administering treatment that suits Jack.  Although I have never tried circadian dosing (not believing it necessary for my son), when we changed from 2 doses to 3 doses of hydrocortisone a day,  weight dropped off him too.  In 2 years he barely put on any weight, although continued to grow appropriately and by the end of that time he was exactly the right weight for his height.  It sounds as if the same could happen to Jack too.   I think all kids are different and what suits one child with CAH does not mean it will suit another, so finding a method that is right for your child can be difficult  but you have obviously done that, so well done!

www.bloodbook.com/ranges.html gives blood test reference ranges.  For glucose tested after fasting it lists 70 - 110 mg/dl as ’normal’.