That is the nice thing about RCBS (I'm sure other companies will be similar), if your nickel plated brass scratches your die you get a new die free. Good customer service!
We run nickel through our press all the time with no issues. I also shoot a lot of nickel in rifles, because the high end hunting rounds are often nickel plated. I have never had an issue with any of it. In SASS there are many people reloading the nickel plated .45LC and .38spl and running it through their lever action rifles with no problem.
My point after all of this is to treat it just like any other brass.