Hi there, Rach how old is he now? I think he needs more A time actually, so I would be tempted to push the nap to 12. Nap refusal for us is always UT these days. I suspect you need an earlier bedtime until it's pushed out.
What is your gut feel? Are you sensing OT or UT?
We had just started an experiment with a later bedtime for Finn, he's really low sleep needs. However, just as we were almost 5 days in, he got a reaction to his vaccines - MMR. So it's a bit of a mess now.
But it seemed to be working, we had to wake him twice this week at 6 a.m.!