Nothing turned up in the search for this, which is surprising. Simply, a lock button for the Object variables window. This is for a couple reasons, actually.
Reason 1: Simply put, so we don't run into the current problem of deselecting the current object while trying to grab another object to drag to the window.
Reason 2: The ability to drag and drop an Object variable from one object, into the current object's graph. This would also lower the bug surface area, as the Object Reference field can be auto-populated, reducing chances of user error.
Customer support service by UserEcho