i'm saying that the entire wafer light should be condsidered an 'appliance', as it is not "fixed in place." nothing is screwed to the structure, until someone tries to require that the termination box must be secured. to take this just a bit further, that little cord whip with integral disconnect from the luminaire to the termination box could not be terminated in a 'junction box,' as the 'junction box' would be permenantly fixed, and should not be allowed to be used as a replacement for permenant wiring.
as for my remark on the box-fill, i was simply going down the path of this thread, in mistakenly speaking from the point-of-view that it was part of the structure. i do not believe it is. IMO - that junction box IS NOT part of the structure, it is a part of a stand-alone fixture. it is it's own luminaire, and need not be secured to the structure, other than those springs holding it in the drywall. as far as i'm concerned, it's a lamp.
getting back to the spirit of my second remark was, what it DOES need, is a bigger box where the junctions could actually have some space in them. those terminal boxes are tiny. the newer wafers are getting better than the first few that came out, but they are still tiny and do not have very many cubic-inches. (speaking of which, they're not marked for their cubic inches). the terminal boxes on troffer lights, are even worse. there's no way there will ever be 4" of conductor inside of some of those chinesium fixtures.