How did the transition to 3 naps look like for you?

I think we are in the middle of the 3 nap transition but things seem so messy that I'm unsure.

My baby will be 6 months in a couple of days. So far, he has been taking 4 naps of 40 min. Bedtime false starts have been an issue since 3 months.

Some of the things that are slowly changing since last week are that a few naps have been 50 min or 1 hr and he seems to tolerate better 2 hour WW.

What is very confusing is that for 2 or 3 days when I try to put him to sleep for his 4th nap, he fights it back although he looks VERY sleepy to me. He fights back all naps, so this is not telling me much either. I don't know if the 2 hr WW is too much. In these situations, he usually stays awake for 3 or 3.5 hrs, but still with a false start for bedtime.

I guess I'm mainly wondering if the transition happens from one day to the other or if it's a messy process. What was your experience?