Yeah I know those spring collars don't work as well on heavier wire sizes. On the 11 gage wire they seem to tighten down good with 3/32 cable. The tubing you use is probably a much more tidy way to do it though.

I don't know how much difference it really makes, but I picture a yote passing through a loop more freely when it's the wider square-shape, with a little less hesitation since there's less chance for his ears or whiskers to brush the cable, compared to the normal teardrop shape which he has to enter it just perfect, both on the left to right and the vertical height.