Totally restructured, meaning "mountains rose and valley's fell", yes. Completely vanishing any and every trace of pre flood geology, no.
"Meaning under YEC sediment should not go back any further than about four and a half thousands years. "
You are reading your own assumptions into YE beliefs. In order to have a strawman to knock down.
"But that 12,000 isn't an age of the Earth, it's the age of the oldest sediment. All it means is the Earth is *at least* 12,000 years old. Equally the oldest human is about 120 years old, but this doesn't make the earth 120 years old."
It means the earth is at least 12,000 years old, IF AND ONLY IF, we have interpreted the sediment layer correctly.
ok I understand now. my apologies