Actually... he's a little right. This problem occurs with water injection before the blower, as well as nitrous. And its more than just eating the coating off (moreso with water injection, as typically you're spraying larger quantities and spraying more often. Wet kits have a greater effect on the rotors for the same reason.

IF you put the nozzle too close to the blower, it won't be completely atomized and you'll effectively sandblast your rotors. As long as you don't follow the nitrous manufacturer's instructions, you should be all good. Tap it nice and far from the TB like Dubster said.

You know.... there is a premade port for water injection on the blower... wouldn't be that hard to rig it for nitrous instead. Assuming Moss Motors did their job right while designing it, there would be a relatively even distribution amongst cylinders as well...