Straightening relationships using a macro

I'm working with the model I imported from PowerDesigner, this time making styles consistent. Some things are easy, like changing the submodel defaults for colours and relationship elbowing. Other things are much trickier - it would be great if I could automatically apply the defaults to diagram symbols but, hey ho, we can't have everything we want.

One thing I want to do is to make sure all the relationships are properly elbowed, and  perfectly horizontal or vertical if that works. I can't find any way of doing this in a macro - in the UI I can use "Reset to Default Docking Position". 

In a macro, can I do these?

  • apply submodel "Diagram and Object Display Options" to all (or selected) symbols
  • run "Reset to Default Docking Position" for all relationship displays

There is an 'elbow position' property on Relationship Display - I know I can change the value, but what does it mean? All the ones I looked at have a value of 5000.