Dear Xara...

This observation is as much for completeness as anything.
They work.

Smart Arrows 1, 2 & 3 are the same arrow family (Arrow 1).
The head ought to allow the 8 head styles other arrows or flow lines have.

Smart Arrows 4, 5 & 6 are the same arrow family (Arrow 2).
The head ought to allow the 8 head styles other arrows or flow lines have.

Smart Arrows 7 to 25 are the same arrow family (Arrow).

Acorn