Finale 27, Windows 10.
The erhu, zhonghu, and a number of other Chinese instruments notate glissandi with a straight line with an arrow head at the end. This is the standard notation and communicates to the performer something different from the Western glissando notation (there is something in the speed and inflection of the slide that relates to traditional performance that is not the same as either the glissando or the portamento in Western classical music). Could this be added on the smart shapes tab underneath the guitar slide line? At the moment, composers writing for Chinese instruments have to use graphics to create their own symbols, but these symbols are not as flexible as the smart line tool.
Specifically: we need two kinds of slide line with arrowhead. One is a straight line (used for erhu, zhonghu, gaohu, banhu, jinghu), and one is a curved line (used in guzheng).