i think that from what i see with the routine that you may want to try having 2 naps still as when lo is waking like that - randomly but often it usually means that lo is overtired. you may want to extend that am A time slightly but i don't think that should be your main worry right now. you do def need another nap as lo is most def getting overtired in the A time before bedtime and therefore seems to be having a very fitful and not a restful sleep at night - so it is now a vicous cycle kwim? i would def opt for a second nap - even if it is just a half hr to 45 min catnap say around 4:30pm. btw what time are you putting lo down for the first nap?
how many bm/formula feedings is your lo getting each day?