Stronger chakra ups base speed which is used then for shunshin. Even for shunshin less of stronger chakra would give good results.Madara has much more chakra than Sasuke, so this comparison doesn't work for your argument, which says that Shunshin is dependent on the power of chakra.
It was base foot speed, with foot speed alone KCM isnt anything special either as its 3.5 enhanced by KCM.That doesn't push him to KCM Naruto's level when it coems to speed. Not to mention Shunshin isn't completely dependent on physical abilities, otherwise KCM Naruto wouldn't be any faster than Base Naruto. Kurama's chakra is what makes him faster, it doesn't enhance his physical abilities that greatly.
He was able to open 4-tails mouth , he has strength to throw FRS. Physical enhancement if off the charts U_U
Nothing is flawed here. A base speed is important for shunshin. A shunshin just like most jutsus have limited amount of chakra that can be used. Exceptions would be V2 stages such as V2 Ay or BM naruto, where biju levels of chakra are pumped.There is no manga scan that shows him being faster than KCM, nothing was trolled in this manga. Its just you fanboys wanking Sasuke as usual. I'm still not seeing any definitive proof. As Turson said, you are offering nothing but your interpretation. An interpretation I'm not interested in, especially since its so flawed.