Hi
I thought I would post to give you a bump and just to say I'm experiencing the same thing with my 6 month old. We are looking at transitioning 3-2 and yesterday actually worked well! Today has not started with a good nap so we will see what happens.
I'm also wondering this same thing and I think the solution or what you will end up happening us that afternoon sleep will become a catnap which will eventually phase out like with 3-2 transition. I would say as the wake times keep increasing you will have to cap one of those naps.
You said the morning nap was the best so maybe stick with that and cap the arvo so your LO is tired for BT.
Eventually that morning nap will move later to around lunch time and you will have just the one nap
Hopefully one of the very clever and helpful ladies will take a look at this for you too. They might have some other suggestions.
Hope that helps you a little x