Have shot and reloaded countless nickel and brass case since the mid 70s. Prefer brass but some nickel cases get in the mix and they are sorted out and loaded seperatey. Have found nickel splits sooner than Most brass, however have sone Fed. nickel 38 Spl case that have been around 10 years?
As the carbide vs nickel issue, carbide is “ harder than Chinese arithmetic” so nickel won’t hurt dies.