Just a quick note to those interested in this thread.
Another developer on the forum has created what appears to be a superset of the functionality I had in my script and is offering it as an actual module for 4.1.x.
As a result, I am encouraging others to take a look at his module. Here are the links for your convenience:
http://forum.x-cart.com/showthread.php?t=36535
http://www.xcart-toolshop.com/productoptionsmod.html