Does the exception state 'on same floor/level'? IF your job falls under that, then it's OK; but....are smokes considered 'lighting outlets'?? I would think 'no'
Have you checked with the local AHJ?? I'm a Jersey guy, and as I said...it will not fly here. The Fire Sub-Code AHJ would not allow one dwelling unit to provide power for the smokes in a common area. IF the areas are not 'common' such as a stairwell for ONLY one of the units, that is a different story.
