Category dropdown retains hierarchy in admin but not in the public-facing form

Hi, great plugin. One issue I noticed is that the dropdown for assigning a category in the admin retains the nested hierarchy structure (see here) while the dropdown in the public-facing page for submitting a new question just has a flat list of every category (here).

IMO the functionality of the dropdown in the admin is the desirable behavior. I would submit this as a feature request to update the public-facing dropdown so that it behaves the way the admin dropdown does. thanks!