Thanks for the comments.
We have low ESD covers and purge covers with hinged lid. Keeping a small positive purge pressure in the cover displaces any moisture that might condense. I have worked with CO2 and LN2 for a long time and have heard very few asphyxiation stories. We offer some alarm units, hand held and connected to the equipment. Many of the larger facilities do have monitoring, I am aware that often people will defeat the alarm which is a big problem. I am kind of surprised that CO2 cooling is less popular, the math I have shown seems CO2 is cheaper. The other advantage to CO2 is the gas concentration in the room has a smell so at least you get some clue, if not visions of beer since that is what it smells like. Nitrogen is odorless.