[calzone]

Well, I figured out how to do option-shift-drag.

Turns out that OmniGraffle forces you to press the key combination BEFORE you click on the object you want to modify.

That will take some getting used to considering in every single other application where this concept works, you can engage or disengage the keys in any order before or after initiating the drag.

In all the other apps, what matters is only what state the keys are in when you release the drag, allowing you to change your mind or preview certain choices as you are dragging.

Is there a reason why OmniGraffle doesn't do it that same way?