This is something that I added to the LabVIEW wishlist.
I use the "no-op" case method that Oleg mentions.
But, still there are times when I have to go back and add another shift register.
In the case of the "HUGE" diagram, you can temporaily re-size the structure so that it is very narrow. This will minimize the mouse action. After all of the case have the new wire, sizer it back up.
Ben