I am so glad you are seeing progress.
You might find now with the good nights that he needs longer AT during the day and eventually less daytime sleep. But can observe and see.
Before my LO started the 2-1 transition I could never let her sleep past 430 (730 BT), but once we started to transition that all changed.
Once your routine settles some keep an eye out for signs of transition. That was/is the next big challenge for us.
It is amazing how much better everything feels/seems when we all get a good night's sleep