Thought some more on how this could be implemented:
If recognising the cross-points automatically is a problem, maybe we could select the points we want to stay sharp before we apply the script?
But I guess you would still need to somehow pick up the continuity between the parts...

BTW. My illustration above from MoI contains some selection errors, in both cases there would be four hard lines that meet in one point if it would be the same as in XSI, but I also have corners where three hard edges meet.

If there is anything I can do to help, please let me know.

Cheers,

Tom