One of the factors prohibiting the use of civil geometry in plan production is that it can often feel cumbersome to implement design changes without 'breaking' your previous work.

Let's say you have an intersection designed using civil geometry, and now the client wants a turn lane added. Now you need to "replace reference" on every fillet for every driveway, entrance, and other intersection on that side of the road. If you have any ruled models, then every one needs to have every ruled reference corrected.

If, however, the tool created a piece of complex geometry which could account for tapers and variable offsets segments, then it would be as simple as right click->add offset section->select station range->select offset(s). Now all of your ruled pieces of geometry like fillets, modelling matchlines/seamlines, etc... keep their original parent element. The new type of offset geometry would behave just like as if you used the existing "single offset partial," "variable offset taper," and "ratio offset taper"tools, and used "complex by element" on the results.

It's very similar to how superelevation sections are containers for superelevation lanes. Offset geometry are containers for offset sections and taper sections.