https://gfycat.com/formalgentlelemming
Not this particular use of it of course, but just in general.
Sorry the cursor isn't there; you can still easily see what's going on though.
EDIT: I rewrote this as a shortcut menu plugin that just opens a regular block diagram window:
Here's the old version in case anyone wants to play around with the External Editor Wizard stuff, or my subpanel diagram code:
Old AHS Editor.zip