This ability should lead to some very creative solutions to design challenges. I absolutely look forward to seeing the inventiveness of some users with this behavior.
To get the creativity ball rolling, I spent a little time on a proof of concept that others had suggested should be possible. Here is just one example of what can be done...
In the next image, first notice that the daylighting is accomplished via a grading as opposed to a daylight subassembly (top arrows). The orange objects are feature lines that have been extracted from the corridor, and made dynamic to it. The cyan arcs (curb return) are feature lines that I added manually, that are connected to the ends of the corridor extracted feature lines. Lastly, notice that the design profile (arrow in the lower left hand viewport) is below the existing ground profile.
The next image is the result of ONE change. That one change was editing the design profile (arrow in the lower left viewport) via a grip edit to be above the existing ground profile. the rest is the result of the corridor rebuilding, the feature lines dynamically remaining linked to the corridor and those feature lines updating the cyan feature line that I add by hand (because they share a common endpoint), and of course the gradings updating as well (2 top arrows) from cut to fill.
Big deal you may be saying. Well think about it. In previous versions I would have had to modify a curb return profile as well, to ensure that the curb lines stay aligned. In this example that was not necessary, as a matter of fact there are no curb alignments, nor profiles.
Talk about a game changer. This ability should also allow us to create cross-gutter flow lines that will auto-magically remain linked without the need for extra alignments or profiles. I also created four dynamically linked feature lines on each corridor, but I could have accomplished similar with only one feature line and gradings from that one, in the curb return area.
Where once I needed 12 alignments and corresponding profiles to do a full intersection with cross-gutters and spandrells, I can do it with only two.
Just Think of the possibilities.
Be Better... Don't do things the old way!