You could not be more wrong and you would understand that in an instant if you tried it. Obviously when doing a standing barbell curl you can try to move as little as possible but as you said its as possible it is not strict your body is absolutely going to move some without the wall. It is absolutely much more difficult with a wall. Why do I have to argue with you idiots about it for 50 pages when you could try it and find out in 30 seconds you couldn't be more wrong but you just want to argue out of ignorance. By definition no wall it's a cheat curl whether you swing your butt and back a foot or just lean back an inch it's not strict and it is much much easier.
We have seen your videos of strict curl against wall. It is eye opening level of strength.
Like I said, in all the gym that I have been to, from east coast to west coast, from US to China to Europe, I have never seen anyone can standing barbell curl 150+ lbs without body against wall, without swinging body, without using momentum to throw the bar up, not even IFBB pros. What they use for standing barbell curl is usually in the range of 70-100 lbs.
I sincerely wish to have the opportunity to see how you can do it.