Ok, on this form argument - a couple comments and this comes from training with a guy who has shelves of trophies and records in dead lifting, owns his own gym etc.
You need to be able to compare what your single rep max was this week to next week to 6 months from now. That is the way you measure progress and if bigger muscles move more weight, which is a universal constant (individual variations aside), it's how you grow. If you think perfect form is god, then the slightest cheat in form will have a huge impact on the weight you move. That means your one rep max is going to be all over the place. Whether you do a perfect isolation curl or I swing to get it up, the muscle has moved through the same range of movement, the weight has been lifted. But if I do everything I can to get it to the top this week then next week I do everything I can to get it to the top etc. these results as they translate to a one rep max are comparable. There is no cheat effect as such. Now I used to argue with him on this and other points but I'm telling you, his way of training just works better than anything I have seen before or trained before. Some things demand better or more strict technique than others of course. Squat and dead lift for example. The better technique you have there, the more you'll lift. I'm just saying that for a lot of exercises, obsession with precise form perfection is counterproductive if muscle growth is what you're aiming for.