To edit multiple Dynamic Corners simultaneously, they need to be selected first. To select Dynamic Corners with the tool, simply drag a marquee that encloses (or at least intersects) the desired corners, just as you would use the selection tool to select art objects. Holding Shift
also works in a similar manner: corners which are Shift-marqueed
have their selection state inverted. Clicking on an empty area of the canvas deselects all corners. Note that selecting a corner does not automatically select the path on which it lies.