Map editors frequently need to add a node to a line that is a shared border of adjacent polygons. It would be great if when adding a node along said line, that nodes would be added to both polygons at the same time.
Right now, I might need to add several nodes along a segment and move them, but I first have to duplicate all those nodes onto the adjacent polygon by hand, since Object > Overlay Nodes does not correctly add the nodes. This involves dragging new nodes on the adjacent polygon with "Snap" enabled until the node is found.