The UI can be better when drawing over an existing shape

[hb20007]

Drawing over an existing arrow is a common way to remove the arrow while keeping all the other shapes.

Let's say I want to remove the long green vertical arrow in the example below:

When I try to draw another arrow over it, this is what I see (2 overlapping arrows):

However, it would be better if I saw this (same arrow with a lower opacity, showing that it will be removed):

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Also, when holding the right click button over an existing circle, it would be great to have the circle shown with a lower opacity, indicating that it will be removed. Currently, there is no animation.