The leaderline is stored as a geometry in
as an IPointCollection with 2 points. No explicit angle is stored for the leaderline.
Hope that helps,
Adding to ArcGIS Pro
We are now at ArcGIS Pro 2.5 and I am still looking for setting an user-defined angle for label and/or annotation for high quality maps. Is there a technique/workaround to set an angle for the leader line? (not the Angle field in the Annotation Feature Class which rotate text).
I looked at all leader line properties and cannot figure out if it is possible to set an user-defined angle. I also looked deeper in the leader line symbol in Callout > Leader line symbol > drop-down menu Format line symbol > structure tab for Global effects to tweak the leader line... but no luck so far.
Does anybody manage to set an user-defined angle on leader line for Background Callout?