Currently sections can only be set and cleared inside the Section/Style Preferences menu. It would be nice to be able to click on the staff and indicate that a section or phrase is to be set or cleared at the slot where the click occurred. Right now there is a menu that pops it with shift-click on the staff. This could be used to get the slot, round it to the nearest whole measure and offer choices for section and phrase settings.
BTW, the Auto Fill Notes options listed may not be functional. I'm not sure when they were introduced but they don't seem to do anything.