I've noticed that sometimes I'll right in a stroke, but it'll misread it as a different stroke(my fault for fast writing). But, it will put the right stroke up in a light green. I was thinking an option to toggle this on/off would be good, if its turned off just make the stroke you made turn red for a second signaling you made a stroke mistake. The reason I'm suggesting it, is my handwritten chinese is horrible even though my reading is fine, don't need the extra help on seeing an extra stroke:)