There are more types of arrowheads implemented than what's available on the interface. In order to add them to the interface there should be a more.../less... link should allow showing/hiding additional arrowheads in the arrowhead popout.

• Add the show/hide logic to the arrowhead popout
• Add the additionally implemented arrowheads to the conditionally hidden section
• Move the T arrow end to the conditionally hidden section
• Add "crow's feet" arrowhead and put it in the hidden section