Hi Frederick,

re:
> Or I could post the links to the two step files that I imported for testing the script.

Could you please post the links or e-mail them to me at moi@moi3d.com?

But yeah if it's when you have several hundred MB of objects some things like storing undo information can become time consuming.

Taking 1 minute to process a heavy amount of objects is not particularly unexpected. It might be possible to tune it up though.

Thanks,
- Michael