Thank you all for your responses! I talked to his dietitian about it today and they moved up his visit with his geneticist from October to August 31 to address these issues and some other questions we had. I told her about how he is such an amazingly content and happy baby unless his levels are a little higher, and she said (like a lot of you said) some people are just less tolerant to phe and notice the slightest raise in their level.
Maverick- Ian is on Phenex-1 and he has done really good on it. Right now his dose for a 6 oz bottle is 1 tbls of Phenex and 2 scoops of Similac, three times a day.