Thanks, Simon! Your change immediately gave me the configuration settings in the standard buttons plugin, but I had another (user) error.

My menu entry didn't point to a category. I wanted the root of the category list, so I just skipped that. I didn't get the buttons on the front end until I fixed the menu entry.

Hallelujah! A big thank you to the folks who forked this application to run in native mode! Legacy is dead.