Hi Katherine,
Thanks for coming back to me so quick.
I totally agree on the 1 nap days the second AT is too long but I have never had much luck with the CN as he refuses to sleep if he is UT at all and my day was getting too long. TBH he handles it very well, not really any NWs and if he is kept occupied he is usually fine. We have had occasional days when he has 2hrs nap but the latest I've got to is about 1pm on the 1 nap days. The only backfire I have are some EWs of around 530ish but if he catches up over a few days these tend to go. These are the days I end up going back to 2 naps. On the plus side he tacks on very well most times which helps catch up.
I've also tried BT 2hrs after a CN and he just rolls around in his cot for 1hr or so and I guess he just isn't tired enough. The CN never worked during the 3-2 either and we had a lot of EWs!
I'll try bumping the AT like you said and see what happens. I know I can't do anything about him waking at 37m because he has had a poop but it happens quite a bit, it's like when he finally relaxes he then poops
its frustrating as I wonder whether he would have had a nice long nap!
Thanks