This is from the dim and distant past but I've a feeling the taper is a different angle on metric and imperial wheels. I could easily be wrong but it's worth a wee check.
I think I may have one of each type somewhere. I'll check tomorrow, if I remember.
Edit: I remembered where they are and just had a look. This is for two 10" wheels one with 4" PCD and the other with 100mm PCD. They are very different. The 4" wheels appear to have stud holes sized for 3/8" or 7/16" clearance so about 10 or 11mm dia. The 100mm wheel has stud hole of 15mm dia and a steep taper. I guess these are meant to fit M12 studs. I'd bet the nut for the 4" wheels would go through the hole of the 100mm and maybe bottom out against the hub before they properly tightened the wheel. They would also contact on only a limited part of the taper because of its larger diameter. These wobble nut things would need to be substantially larger diameter than the standard nut for a 4" wheel.