Having said which ... :-)

Although the script itself doesn't refer to mid-points, it does look as if Omnigraffle is creating unrequested mid-points when a shape with bezier or curve connections is moved by automatic layout or script. Particularly when the rank separation (generation gap) is small.

For the moment, using the inspector to remove midpoints is the obvious solution. Haven't been using bezier lines myself, so thank you for pointing this out – I'll take a closer look at it at some point.

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