Normally i would say Choose LST they respond very well on it. But if you have an good and fast growing strain and a good feeling then Do Toppping and LST. I grew a lot of automatics this season and i did i different on eachs strain, maybe on each plant. In my previous grow i Did Fimming And LST on one and topping and Lst on the other. And In past grows i just picked away some leaves . But i recommend you Highly to do LST. Happy growing, gonna follow up to see how it works