Hi Brian,
thank you for this documentation. Great!

>>Maybe MaxS could provide a way to change the order of the input slots?
This feature was in my todo list for a long time :) And finally I made it today.
You can download updated version from my site:
http://moi.maxsm.net/files/nodeeditor/ne.swap.macro.io2.zip

Now you can rearrange inputs and outputs of any macro node. Hold Alt(Option) key and drag input/output dot.

I didn't test it well, so there can be some bugs.


P.S. file updated (bug fixed)