It double boots on mine (OS 3.1), but since I'm running from CF and my screen stays black during the boot process I don't even notice except for a quick flicker of the power LED. No big deal.
And thanks for the comments @mfilos! I just discovered your blog somewhat recently and have really been enjoying reading about your projects!
Last, any tips where to get the author's updated workbench.library? Obviously going to Aminet and just typing "workbench.library" into the search would be too easy.

Is this something I would need to compile myself, somehow?