first off just want to say you display some aggressive, unpleasant, and somewhat frustrated behavior. You should realize when people post a response to your question, they are making an attempt you help you, a complete stranger, and to get get frustrated with them because you feel their answer is not correct because you may have already tried it and it hasnt worked or you feel that it isn't 'concrete'
The reason people may not always be able to solve your problem is because there are so many variables in growing cannabis, its like where do we began on what could possibly be going wrong..
With that being said, you have said you have tried everything, so im quite sure there is nothing i can tell you to try, that you havent already done so.
Although, i do feel that you shouldnt have any stunted growth due to slight cupping curling up and down as long as it doesnt progress any further then the tips and doesnt discolor.
I do hope someone with this problem may be able to lend some knowledge, but just know it comes down to figuring out how to communicate to your plants and sometimes you have to change everything and one at a time bring one variable into the equation at a time and see when the problem arises.
Good luck
