Thanks for the routine:). So generally yes, I would say it's time to push the morning nap or cap it. Tracy doesn't propose detailed routines for 6mo+ babies, she is rather suggesting following baby needs. We here are more strict, haha:) or rather more concentrated on A times and amount of sleep kiddos have - mostlly because if people write here, it's because they HAVE some problems with sleep mainly.
So... there are two options you may go and it's your choice how to tackle it:1
1. Push the morning nap and make morning A longer. I would go for 8:30/8:40 in one go, no more. Then push the afternoon nap by 15-20min. I would still keep the catnap, but probably a tad later. BT can be 2h after catnap or earlier if you think he needs it. The problem with that routine which I had is around 3.5h of daytime sleep. With 12h day it may be too much. No matter how much I pushed the morning nap, I couldn't get 11.5h nights with 3.5h naps. So I ...
2. Started capping morning nap. So I stopped pushing but capped it at 45' and then even 30'. I kept 3 naps routine for a longer spell thanks to that but overall daytime sleep was max 2:45/3:00. My DS nights improved immediately.
Many mammas have great success on working on 3h of A and 2x1.5h naps + 13h days. We never had it here:) but it's your decision made of your son how to proceed further! HTH