Engineer or not, all I can say is that one out of every 150 re-loaders I talk to have had an issue with the nickel platted brass. It will sometimes flack off and imbed itself/stick in the die body and start to scratch the brass. Some reload their whole life and don't have problem and some don't. I to believe it could be the quality of the die body, as I had a problem with an new die and from the start it scratched my brass and had to be replaced. (Something about it not being polished) it was replaced and I moved on. (Bad out of the box not from nickel platted brass)
So if you must reload the nickel platted brass then I would suggest that you buy a cheap (In price not necessarily Quality) sizing die and move on. If it reloads the nickel platted brass for the rest of you life then so much for the nickel flacking off and scratching your other brass and if it does start to scratch your brass then just buy another cheap sizing die and move on. I have a few of the nickel platted brass and will start to reload them when I find another resizing die other than my good one i had replaced. But here again, the chances of the nickel platted brass harming your die is low but as the saying goes, "I'm the unluckiest guy I know".
Not sure about the nickel plating cutting into the die, last time I looked all the nickel plating has to do is just stick to the die body to cause the problem. But as far as being hard, when was the last time you cut off a catalytic converter of a 1979 Ford pickup truck? Never mind, maybe that was a harder nickel alloy.
I guess that is platinum, rhodium and palladium. I just remember them being hard to cut.