I find the flexibility/customizability of the Label & Status drop-down menus extremely useful. I just wish there were more of them (customizable drop-downs). And I wouldn’t object if you were to add check-boxes, as well.
So, here’s a plug to make all custom meta-data text columns/fields convertible to drop-downs and/or checkboxes (as in Omni-Outliner) in a near future revision of Scrivener.
Many thanks for listening/reading.