Punching the ground ? Why would she stomp the ground with no knowledge + 1v1 without her knowing it's a bunshin ? that logic is beyond me.
If she was all for stomping the ground she would've done it last chapter against Madara, but she runned and try to punch him head on, she even did it with Sasori so what you say is incorrect.
And what you say is true Byakugó is a splendid Jutsu, but sadly it won't be enough against Kidaichū Mushikui
First of all Kidaichū Mushikui is eating Flesh
and Chakra, she might be regenerating the flesh but, her chakra will go away quickly, Not to mention that the insect will grow inside Sakura, If she keeps regenerating they'll only grow bigger. Just look at the Juubi clone who is larger than Sakura.
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They insect's which came out are
huge Sakura would explode due to the pressure of them trying to crawl out of her skin, I'd like to see a scan of him having hard times controlling it
(I Can't find the chapter)
But it's not even needed the clone only has to distract Sakura for a few seconds which is enough for Shino to use Kidaichū Mushikui.
He can even distract Sakura with the clone and use Hijutsu: Mushidama to completely restrict her movement and infest the bugs to explode Sakura's body.