As I said before, UVs are very important for Maya Fur. I certainly read that everywhere I find anything about Maya Fur, but those sources neglect to state what exactly makes for good UVs for fur. In addition to my previously devised UV sets, I tried a couple alternatives. The two most different approaches are on display here.

In the upper half, we have ZBrush's automatic Packed Tiled UVs. Every Quad's UV is exactly identical in size (there's some odd artifact that scrunches the corner of a couple of them.) They are not, however, oriented identically. Or maybe they are and fur still doesn't reflect that. Either way, the fur default (as in no directional painting) is an absolute mess.

In the lower half, we have the opposite approach: minimize the number of seams by using ZBrush's unwrap function. What scant evidence there is available points to minimizing seams as being the best idea for fur UVs. However, that is not at all apparent from the default result! The wrap around does something horrible to fur direction and again we are left with a mess. I even ensured this wasn't a problem with ZBrush by recreating the cut and unfold operation in Maya using the UV scripts I developed last time. It looked even worse!

My original UV set had the best default look. Admittedly, I didn't try painting the minimal-seams one with direction, but the placement of its seams would left the fur direction painting looking rather... unseemly.