Speaking for me personally, needing high precision control over details like that (spacing of the arrowheads) is not necessary for me. A simple clean default style would do nicely. Perhaps keep the arrows and lines highly editable somehow, so you could tweak appearance in AI or something like that if you need. But getting the basics down in MoI would be terrific and i believe that would fit and be perfectly suitable for most of us MoI users.

Thanks for keeping this in mind Michael.