It seems like you got the first A right, so that's good.
Your second nap is usually 30min? That would be for most babies an OT nap, but it sounds like he is UT for it of he wakes up all happy and chatty. So I actually think it's not your first nap that throws off your day, it's the second, and if you get the second A right then the rest of day will fall into place.
IIWY I would try and increase the second A to 1:40h for now, so almost like the first A, and see what you are getting for the next 3-4 days. Only on the third day you can make conclusions WRT the new A. If you'll get 30-35min naps then it might have been too much for him, but if he is napping 45min-1:20h long naps then he might actually be ready for more A time. What you are aiming for is for him to nap 1.5-2h.
What do you think?