I know the difference between the Byakugō seal and the "Sōzō Saisei" regeneration technique. What provides an increase in strength to the user is the opening of the seal, when it opens the seal with the "Infūin: Kai" is when the chakra is released and reinforces the user's power on an unknown scale. But in all the examples you mentioned, she’s not wearing that seal, she’s in base form, and the worst of all are her examples against Kaguya, which are nothing more than PIS, they could even have a minimum of validity if she was 100% and with the Byakugō active, however it is not what happens, quite the opposite, it is an exhausted Sakura and in the base form. Basically, no physical feat of her in the war is with the use of the Bakugō, it is always in the base form, just awakening the seal does not increase strength, what does increase is releasing his chakra in the body. Base Sakura of the fight with the Juubi and Kaguya clones is the same base Sakura from the beginning of the war, there is no implication that she suddenly gained an increase in power in her base form, as the Byakugō has no effect if the seal is not open.
Is it really plausible that Sakura, without any increase in statistics in the base form in relation to the beginning of the war, has the same physical level as Naruto KM1? If you say yes, you are literally saying that she was faster than the Tsunade and the Raikage since the beginning of the war, does that make sense? I think not. About her against Kaguya is even worse, it's the same version from the beginning of the war, but exhausted already, and managed to react to something that even Naruto and Sasuke had dificults, and was able to hurt Kaguya. This literally puts Sakura from the beginning of the war above Madara Jin, bruh ...