How many total ounces is he taking throughout the day? That may be a better guide for now, as you really have to adjust EASY for your own baby and family.
As for the 45-minute nap thing, Josie got into a pattern where she was waking around 4-5AM and then not getting back to deep sleep, so when she woke for the day she was already on the tired side and able to handle only an hour of A time before the tired cues started - but that wasn't enough A time for her to sleep for more than 45 minutes, so we ended up with 4-6 of those short naps a day just to get us thru the day without ME melting down from HER crying nonstop.
Once we got her A time adjusted, which we did by stretching it gently maybe 5 minutes every day or two (she was about 14-15 weeks by the time we did this, so older than yours), and we learned to help her transition to the next sleep cycle - by then she was waking out of habit, and her cry wasn't a fussy "I'm still tired" whimper-cry but an "I'm AWAKE and I can't get back to sleep" upset cry which she NEVER settled from - then Josie began napping longer. Our finished EASY included 3 90-minute naps a day instead of the target of 2 2-hour naps and one catnap, but it worked well for us and we could plan around it.
We have a post at the bottom of the Naps FAQ's about it.