Truly No-Glue-To Shapes (http://www.visguy.com/2016/07/12/no-glue-to/)
This article also discusses a workaround where the normal "don't glue to me" settings don't work. The situation is this:
You make a shape that uses the Developer > Behavior settings for "not-gluing-to". However, if you Ctrl + Drag a duplicate of a connector, the settings aren't respected, and you still get the connector trying to glue to your shape. It's been this way for a long time, and is still an active "issue" in Visio 2016, as of this writing.
Thank you so much for this nice article. I was trying to find a solution for the same problem.