If there is a way to do it or it has been suggested then forgive me.Quick illustration ...
See the house on the left, I add two points to the right side of the roof to add a chimney, select those two points and drag and end up with house 3. If there was a way to pull the segment to end up with a shape like house 2 (sorry they are out of order) it would be useful I think -just for speed. For example you draw a wall and want to make crenellations like a castle wall, use the Split tool to add points, grab groups of two skipping one point between each group, drag using 'segment mode' or whatever, instant crenellation or teeth or chainsaw blade etc.
Also to go with this on the top you will see an example, if you were dragging using this 'segment mode' and could hit a key to insert a line segment while dragging you could more quickly build certain types of shapes. Maybe you can think of it as a 2D version of the 3D extrude.
