I have reloaded several hundred nickel plated cases in 7 mm Rem Mag and 25-06. No issues with flaking of the nickel, and I probably got a solid 3 reloads out of the cases on average before the necks started to crack. Which is maybe a single reload or so less than I see out of the solid brass cases.
Because of the nickel's hardness compared to brass, I would always throw out any deeply scratched cases to protect the rifle chamber and the dies.