This is how you can create and edit the line end shapes that come with SIX. Requires some basic to advanced Visio skills. There are two parts. 1: How to name and create a new line end. 2: How to distribute the new line ends to other users in your company.
Visio custom line line ends can only exist in a drawing. In order to distribute we created some code that takes a special custom shape and uses that to populate new drawings at startup. Too complex to explain the why, but here is the how: