adding connection points to Zigzagline and Polyline?

["Roby, Clyde G" <roby ida org>]

Hello,

        On an initial Standard Line, there is one connection point.  You
can easily add more connection points to Standard Line (right-click and
then, in the pop-up menu, select "Add connection point").  Similarly,
you can delete connection points on Standard Line.

        Is it relatively easy to add the functionality to do the above
on Standard Zigzagline and/or Standard Polyline -- in the middle of a
line segment?

        Thank you.

Clyde Roby