You can keep the main top and still supercrop.
I harvested one last night that just before putting into 12/12 I bent the main stem, which was quite thick, at 90 degrees about half way up the plant.
The plant was about three foot tall.
It stayed bent at 90 degrees and the branches grew straight up and made about 6 or 7 main colas.
There was very little popcorn, just main cola's, including the original main cola.
You can also top once, and when the next two main branches grow up and become the main growing points, you can supercrop them to 90 degrees, and then when the two branches below grow up taller than them you can supercrop them too.
Topping and then supercropping you get more buds, as you get more bud sites than just bending the main stem over half way up, but more of them are smaller buds than just bending the main stem over, which just gives you main cola's and little smaller buds.
Which is the best? I don't really know, as I have only been supercropping for two grows.
I think topping first and then supercropping after they have regrown a bit will give you a bigger overall yield, but while I have grown both together, you couldn't really tell as the one's I just bent over at he main stem, or left untopped and tied the main stem down, they were the smaller plants which were behind the other in veg, and they weren't ready to top when the other one's were, and by the time they were ready to top the rest were being put into flower, so I didn't have time for them to regrow from being topped, so just supercropped them over half way long the stem or tied the main stem down.