MI (mineral insulated) Cable in building stairwell

[Grouch1980]

Hi,
I'm aware the building code in NYC (and many other jurisdictions) prohibits conduit / wiring in an egress stairwell without being enclosed in a 2 hour fire rated enclosure, unless the circuits are for loads specifically within the stairwell.

If you route MI cable in the stairwell, which has a 2 hour fire rating, would this free you from needing the 2 hour rated enclosure?

 

[infinity]

I'm guessing but I would think that it would not require a 2 hour rated finish around it. It could be interpreted as being subject to physical damage which may trigger other protection requirements.