with "some cheating" I mean controled cheating in a sensible way to break through a sticking point. Not any acrobat feats.

I find that for biceps for instance when I use mainly scott curls and other super strickt no cheat exercises then I gain NOTHING. Neither in strenght or size. No matter how sore I feel afterwards.

But when I throw in heavy ass barbel and dumbel cheat curls my gains go through the roof.

Same with back. When doing mega super strickt barbel and db rows they dont do **** for me. But with a little cheat in there my gains takes off.

Is using to strick form just counter productive(in the exercises where you can cheat safely that is)
Can it be that the body is built for all muscles to cooperate and when trying to focus on one muscle exclusively you cant utilize it to 100%??