I had this idea (which always gets me into trouble) to draw a vector arrow (tail to point - line draw 0 to 100), then undraw the tail (line draw 100 to 50). Since this probably makes no sense, here is a GIF I created using 2 arrows (blue is tail to point, green is point to tail) to demonstrate what I am after.
my question - is there anyway to do this with a single vector shape?
In addition to the dash/gap method, for this case you can also have the line draw exceed 100% to achieve this effect -- probably animating to around ~140% would work. This just has to be manually input into the text field since the line draw slider only allows entry from 0 - 100%.