Option-drag / alt-drag to duplicate should support applying the modifier key after drag start

[michaelmee]

(using macOS)

When alt/option-dragging to duplicate an object, it would be helpful to allow the application of the alt/option modifier key after drag start.

Additionally for drag duplication, the cursor can change to indicate the intent to duplicate while dragging with the modifier pressed.

[Old Bruce]

But that would break the option key's ability to turn off the Snapping while dragging. I use that quite often.

As for the second suggestion I wholeheartedly agree with the idea of showing we are making a copy.