I don't think he is OT. yes, yesterday was a bit OT (because first A was a tiny bit longer resulting in a 30min nap) but the day before and all other days you posted he is UT, not having enough A and having 45min naps (which indicate UT). I am not sure what else I can advice other than increasing the A, and I don't think another sleep board will tell you any different.
On this day, for example (which is the 4th day):
9.40-Awake
11.15-Feed (very sleepy, I have to wake him up by switching side and keep talking to him...)
11.55-Sleep(car)
12.40-Awake
14.10-Feed
14.20-Asleep
It still looks like his A is too short. The A before the second nap was 2:15h and followed by an UT nap (which could be because he was in the car...) and the third A was 1:40h, which is really not enough for him.
I hear what you are saying, that he seems so tired and hard to push the A times, I have been there myself, but as long as his A times are too low for his age he is going to keep napping for 45min. That's at least my opinion.
If you are totally convinced he is OT then you can give him a couple of days to catch up on sleep, so on those days you don't look at the clock at all, just follow sleepy cues, offer as much sleep as you think he wants, let him fall asleep on the breast and AP. After those couple of days he should be more refreshed and you can start again. You can offer 2:15h A time for the WHOLE day, you'd need to stick to that, though. After 3 days you'd offer 2.5h A time for the whole day and see where you are at. If you are still getting 45min naps then you can increase it to 2:40-2:45h A time.
