Spline leaders are fun. They’re not fun in the sort of playground, video game, action flick kinda way. They are fun because if you need them, you can now make them with the freedom to shape them in many ways. Contrast that with dimensions. The most fun you have with dimensions is deciding how far to offset them from the model edge. I’ve been doing that for years, and the word “fun” doesn’t really come to mind. With spline leaders, you can actually take a moment of your day to draw without strict conformity. It’s not a big moment, but it is a nice one.
Spline leaders are avaiable for notes and balloons. They work the same way for either.
To add spline leader to an existing balloon, select that annotation, then click on More Properties button in the PropertyManager. Find the swiggly lined icon and click it. Then, use the control points to manipulate the spline leader as desired.