Well I am going to confuse things with different advice (not to say that Layla is wrong, babies are all different and it's hard figuring ut what works for each one!). I would think those long naps are more likely to be catch up than causing UT since he is on the young side for one nap, and it's a big jump for them even if they're ready for it. It's a big A increase when their day is only broken into two instead of three awake times. IME it wouldn't be too much day sleep even if he was STTN. We didn't have to think about capping at 2hrs until closer to 18 months. That's just my experience, but I've read enough on here to know that a lot of babies do long naps AND nights when they first make the transition, so I don't necessarily think reaching his sleep 'quota' is an issue yet. That's not to say everything was perfect when my DD first went to one nap, but I tended to put any sleep problems down to teeth, development, and yes the 2-1 transition but not necessarily that there was anything to 'fix' yk? I think sleep disturbances are pretty much unavoidable with this and you can drive yourself crazy trying to figure it out. I think as long as you have a good routine going there's a certain element of just riding it out. By all means try some different things, but I do think your routine is good. I would be concerned about capping the nap and getting OT. But again, doesn't mean Layla is wrong... just my thoughts! You might find if you keep him at 2hrs max you get perfect nights!