I'm not sure how a 3d section box will allow for more flexibility for changing depths in a view that has a standard section depth and cut, but allows for region alterations to that depth and cut location.
For example, let's assume a building section is drawn at a particular location. The building overall section does not need to jog: it located exactly where it needs to be to show the most amount of information and relationship between elements. How, let's assume that for a small region of the section in the ceiling plenum, there is a duct being cut diagonally that we want to show cut plumb. With a section region, a small region of the parent section can be altered: cut plan and depth.
The software code is already written for the plan region and a port to the section views might not be too difficult, as the function already exists in the software.