If you have an attic the ductwork is surely above the ceiling joists, and flex at that, so shouldn't be an issue with remodel can locations. If those are the roof rafters (like in a modular home) just place the lights given the ductwork route. You can always use wafer LED lights to avoid problems.

Make a floorplan sketch of the area, because even though the spacing between 4" lumenaires in your scheme falls correctly around 3'-4', placement around the table is unnecessarily lighting up the floor and looks like it would throw into the stair area.