should be obsoleted by this feature. individually good, even better if you can do it en masse.
as an admin I want to be able to to convert a single existing legacy topic into a voting topic so that I can [have UI consistency throughout topics, reap more of the established benefits from this feature, compensate for not being able to holes in the existing feature, i.e. not being able to require all topics to be voting topics globally]
UI for individual:
the UI can be exactly the same as when drafting a topic, except while you’re editing one.
UI for mass:
I’m not picky. shell command is fine. settings check box is better