OK, I figured it out.
I had actually already done exactly what you described, but what I just now figured out is that I need to change the
template's attributes, not the item's, in order for the attribute to show up in the Item Attributes Pane. That was not at all obvious to me. But then I had yet to explore templates.
Minor typos: In both the Help files and online manual, the referred-to "Attributes Editor" is just "Attributes" in the actual window title. It had me looking for the former when I already had found the latter. BTW, your documentation is way better than mine ever was
