Alright, that didn't clear up too much.
I always top at the beginning of flower...
that's the best time, so I've learned.
It should not be hard at all to detect a male,
regardless of topping or not.
You will def. know when you see the pollen sacs
formulate, and should have plenty of time to kill
it.
Sorry if I'm missing the point, but could you elaborate
further...