How early can i top?

I know this probably has been asked a lot but i can't seem to find the exact post. Im growing a really short strain, but i want to keep it extra short. (yes yield and size is already considered). I was wondering it i can top as soon as i see the 2nd set leaves?

you could, but i wouldn't. Wait until there a few nodes under the place you want to top, to allow enough branching to make it worth your while