I'm adding canless recessed light fixtures to my man cave. Drywall ceiling with loose fill insulation within the trusses and batts over that. These are the lights with the small wiring box connected to the light itself, which snaps into a hole in the ceiling. The wiring box is very small, and contains hot and neutral pigtails with the fittings to insert supply wiring. My problem is that I want one of the lights on a three way switch circuit from the entry door to the exit door. With two 14/3 wires w/ ground, plus the factory pigtails, I can't imagine getting all those wires and wire nuts inside the little black box.

The black box is simply inserted into the hole for the light and rests on the drywall above. The only way I can come up with is to do the three wire wiring in a covered junction box, with a two wire drop from there to the little black box, then insert the whole assembly into the hole and rest it on the drywall. That goes against what I know about junction boxes (accessible and fastened to a structural member). Is there a standard way this is done?