Can I ask what is your ideal routine anyway? Is it the 8.30am WU / 9pm BT that you posted above? Or would you ideally like him to get up & go to bed a little earlier eg 7.30am WU / 8pm BT
And when you mention EW, how early is he actually waking at the moment?
Its actually been BT thats been the worse and only recently naps.... could he be too OT at bedtime from too long a pm A as it does seem hes very hard to switch off...
Yes he could be OT at BT b/c you are right it is a very long A time in the PM. So in the first instance you could try putting him down a bit earlier & see if he settles better.
However, I would really recommend you extend his A time in the AM. The short nights are related to the nap being too early in the day and the A time to BT being too long, and so by extending the AM A time, (and reducing his PM A time) this will balance out his day more, and by capping the nap it will remove his opportunity to make up for lost night sleep at the nap. The result is that he should settle at BT more easily, AND the NW/EW should disappear.
You could do this either by:
1) if you want to keep the 8.30am WU, by very gradually pushing the nap later, by 15mins per week, until the nap starts at 2pm, capped at 2hrs max and at the same time aim for BT being no more than 12.5hrs from wakeup time.
OR
2) if you want to shift his routine earlier you could try gradually bringing his wakeup time earlier e.g. if you ideally want him getting up at 8am, you could gradually wake him 5mins earlier every few days until he's getting up at 8 instead of 8.30, but keep his nap at 1.30pm, so his AM A time will gradually increase to 5.5hrs. At the same time you could cap the nap at 2hrs max & gradually bring BT earlier until he's going to bed at around 8pm.
Either way, it will be difficult, especially while his nights are so short. So you may have to hang in there for a while & ride out some OT. And offer an earlier BT if he really seems to be struggling.
We recently did this with DS who was napping at 11ish for 2-2.5hrs, & he started to wake really early at 5-5.30am. I pushed his nap 15mins later per week until it was 12.30-2.30 & at the same time I pushed BT later until it was 7.30. It took about 4-6 weeks to get the nap times where I wanted them, and during this time his wakeup gradually improved & for the last couple of months he's been up at 7am & we've had a nice 2hr nap. The EW have come back again, so now we're capping his nap at 1h 45 & it seems to be helping.
I do think capping the nap may be the way to go, but I think you need to address his A times first before you do.
What do you think?