Korone didn't even have a one-on-one collab with Fubuki until the summer of 2022.
Just recently I was wondering if she and Nene had done anything together, and came across this clip of her pointing out that neither of them is really taking any initiative:
Korone almost never asks anyone to collab. She doesn't want to be a bother to anyone. If someone asks her to collab, she'll usually agree, but she generally won't be the one to initiate it. It's a shame, because she's very entertaining when she collabs with other chuubas, but it's not a common occurrence.