In your first post, you mentioned the fixtures are not listed for use as raceways. Art. 410-31 says specifically that fixtures shall not be used as a raceway for conductors. Exception No. 1 is for fixtures listed for use as a raceway. In several places in Art. 410, there is mention of an outlet box. I remember in the past that we were to design with outlet boxes, however I can't seem to find the requirement in the Code now. Although, check 410-67(c). Several commentary illustrations show an outlet box within one foot of the fixture, therefore, I think an outlet box adjacent to the fixture is the way to go.