Good evening Julien,
I would have to say that 9.5 does not apply since it doesn’t meet any of the applications. None of the units share a common means of egress and none of the units seems to fit the definition of a boarding, lodging or dormitory. I think it’s fair to say that Part 2 is your only option. However, it doesn’t speak about attic hatch anywhere in the code. Not even Part 9
If you have a ceiling that is covered with gypsum or similar product that would typically have 30 min FRR to prevent fire spread through the attic space into the adjacent unit. As a Chief Fire Official, you have the right to ask the owner that the attic hatch be of same rating (hatch door) as the ceiling by either covering with gypsum or install an approved fire rated hatch.
Not sure if it helped.
It’s a good question!