Yeah supercropping is outdated, a bit. But then again I supercrop the shit out of my plants. I also do the lst thing at times, but I've been doing alot of expirementing with fimming topping also. Its natural for your stem to turn a bit dark when you pinch it, it will heal in time. I only pinch my stems abouyt halfway through when I supercrop so that the upper part of the branch doesnt lay completely on itself folded over, but just enough so that it stays bent from the pinch. I have my vegging plants under t5's and they usually start turning their branches back upwards in a matter of hours.
That plant in the middle row all the way on the left, is some og kush I have that hasn't had anything done to it, besides supercropping. If you ask me it looks like lst but its not. It comes down to what you want to do to your plants, the majority of growing is learning, I say you keep experimenting with different methods and see what works best.
If you want to keep trying the supercrop technique, don't do it I recommend doing it above the 3rd or 4th node on the branches like where the circles on this picture are.
Me personally, I've been doing different things to different branches on each plant. For example, I might fim on branch, top another and supercrop a third.
Apologies if my post seems a little bit rambly, I've been smoking on some gdp for the past couple hours lol