It is what it is. This being open source, things happen, and there is
insufficient motivation to change it, or no perceived need compared to to
other development plans. You can try to make a case for the change or take
on the development yourself.
Myself, I never considered it to be an issue, or
When I draw a zigzagline from one flowchart symbol to another, for some
flowchart symbols (process, input/output), the zigzagline behaves similarly to
a line for connections, where it connects the edge of one object to the edge of
another. When I try to use any other shape with zigzaglines, the