This came up during a discussion on the thread on scripting, where I do think it is very relevant, but it was pointed out that this could be considered an independent feature, so I am opening this new thread to track this one independently. It would be nice to (in effect) be able to re-open the brush editor, connected to objects already on the canvas, to allow brush parameters such as size variance, opacity variance and the like to be edited for strokes already applied to existing objects.