I need help which parallax slider is actually the bets on the market. I have tested many but some have issue when there is animation. it will be completely corrupted when there is animation and transformation step.
There is no best. I have not seen any parallax slider code on the internet that is worth the price if a postage stamp. If the effect is really important to you then if you have the programming skills do it custom, or hire someone who can show you examples of their work that is close to what you want.
I don't really understand what you are asking. When you find a plugin you like, it either works the way you want it to or it does not. If it does not work the way you want it, then you change it, discard it, hire someone to fix it, or ask a specific with enough detail so the question can be answered.
Without knowing what you want and what you have it is not likely that anyone can come up with a solution that matches what you consider "the correct way".