A few times I’ve found myself wanting to swap a few block in the Matrix with a few others in the same track. Currently this requires a little shuffling around.
What I propose is have one of the modifier keys work with dragging to swap selection with destination. Modifier + Click is already different from Modifier + Drag.
Ctrl+Drag is used for Copy Selection so can’t use that.
Alt+Click/Drag with Focus the Matrix if it hasn’t been done already. It might be good for workflow if this can be done without focusing the Matrix.
Shift+Drag currently does nothing but behaves as a Shift+Click in a new position as you move the cursor. I suggest Shift+Drag becomes Swap Contents. And the Existing Shift function happens on release of mouse button, like it does for Ctrl+Click.