LMP, you are a master of investigation (and must have more time for it than most of us), not to mention a major contributor of info to so many; I have seen your helpful posts all over the forums. i appreciate your detailed approach and plethora of photos and diagrams.
What would you see if you fit the actual hubs of the SX4 and the TS on each type of wheel (114.3 & 115mm)? Would you see that the wheels' tapered seats for the wheel lug nuts are concentric (or not) with the 5 studs protruding through? That should be a easy visual check for size match.
Best regards,