Well, 10 mins might not make a huge difference to your nights, but I *think* you said he settles & sleeps better for 2nd nap with that slightly shorter first one?
He might just be at a stage where he has a shorter night because of still needing 2 naps, but if you feel it is too short and he's getting tired in the day, you could try capping first nap more & moving 2nd nap & BT earlier to give chance for a longer night?
You might as well continue with this thread even though he's 1, but I could move this whole thread into toddler sleep and continue there.