My 2 1/2 year old is only on 1/2 Florinef per day.  They are .1 mg tablets, so she is getting .05 mg per day.   1 1/2 tablets seem like a lot to me, especially if the blood pressure is constantly high.  Our Ped Endo is always checks our daughter's blood pressure at visits and takes the reading quite seriously.  Having said this, I believe that there are varying degrees of salt-losing and not all children will be on the same level of  Florinef, some will require more than others.  I would still question why they are ignoring the high blood pressure readings.  I guess the plasma renin results may be coming back within the required range and they think this is an indication that the Florinef dose is correct.

Good luck.