[PYenner]

One possible advantage of using VMA lines for a fantail.

The slowest line sometimes (recovery) gives an estimate of what your exit price might be.

In this case magenta is the slowest line and since it gives the longest flat line during a recovery, then you have a nice fixed estimate of where your trade might end up going.

Recycled another pix.
Try to see the general idea, when the fantail diverges, all the lines will eventually converge again. In the case of a recovery, the faster lines "chase after" the slowest line, so that is where they will likely meet.
Magenta is sometimes a guide to exit price.