Multiple guys I know have dropped chains during races with narrow-wide and standard der. "Oh, I've tested it out, it works great!"

A cheap reliable setup is BBG bashguard on the outside of spider, singlespeed chainring (i.e. no ramps or pins etc), and N-Gear Jump Stop clamped to the seattube. I ran that for 2 or 3 seasons with no problems. I currently prefer 2x10 with 36/46 or 34/44, though.