That night sounds like he might have been OT. I know you've had days when there was very little napping due to the sleep trianing but he might well have had so little on those days that he just crashed out for a good (or better) sleep in the night or it could be that during the sleep training he was more prone to skip nap 1 and have a decent nap 2, the second nap being longer held off too much OT before BT helping with the night. Just my thoughts.
So, he had a day with two naps which were not restorative. We consider 1.5hr+ to be restorative. Now there are lots of LOs on routines of 2 naps of 1hr each and they seem fine, there are some in the EASY samples I've seen, but generally we'd suggest one longer (1.5-2hr) and one shorter nap rather than two short naps.
OT at BT can cause increased number of NWs in the early part of the night sleep, it can also cause EW (early waking) and an inability to relax and resettle well at the EW. A nap coming too early in the routine can also cause EW.
Did you move the morning nap time a bit later yet? I would think now you need to look at settling the routine so that you get the one long nap the same each day. Always the morning nap or always the afternoon nap rather than it changing back and forth.
Also day naps, if he wakes up happy as larry even though its not the full 1.30 do we try to get him down for the full 1.30 when this usually means him getting very worked up. Surely if he wakes happy he’s had enough sleep for that time of day?
Well, kind of yes and kind of no. If he wakes happy as Larry AND remains in a good mood all day AND sleeps well at night, showing no signs of being OT at all then yes two short naps are fine and he is having enough sleep in the day. It is when the entire routine is working well that you know the nap length and night length are all fine. If there is anything "off" such as multiple NWs (which are not for food), EWs, nap or BT resistance, or just a generally grouchy baby who looks and acts tired for much of their A time, well, in that case waking happy as Larry is just to fool you
LOs can and do wake (seemingly) happy and totally do not realise just how wrecked they are going to feel in an hour or 3.
if he is going down for nap relatively well now (ie sleep training is coming on well, he is going into the cot awake and beginning to self settle) then routine is where you look when naps are not the full length. At this point I would only do PUPD for the remainder of the nap to help him learn the habit of napping longer where he is supposed to take a long nap, rather than doing it at both nap times I'd just do it for nap 1 and leave nap 2 shorter as I think I mentioned in a previous post. But just doing PUPD on it's own with the nap at a time which is not suitable is not really going to be helpful.
If you have already moved nap 1 15 mins later and if it has been 2-3 days of short morning naps then I would suggest moving another 15 mins - or post todays EASY times and I can have a look. Along with that, if you see a longer morning nap in your records but it was a day he EW then he likely still needs the nap moving. Hope that makes sense.
Shame everything is not a set routine, would be very handy!
ha ha yes it would.
Honestly when you get a settled routine it feels predictable and kind of feels set even if it is not. Yes there are changes when LO sleep needs change, naps are dropped and so on, but they are blips in the scheme of things and once the new routine is worked out it can all carry merrily along for another good while again. Sleep needs and routines do change in the first couple of years.