This is the money idea !
Assemblies that attach to feature lines instead of alignments. Oh Happy Days !
I strongly disagree. You should be asking for the subassembly you want to attach to the feature line as a Civil 3D object. That way you can label the object instead of a surface and have the ability to have two points located at the same XY location with different z values.
You lost me. I want to take a subassembly (ie curb and gutter) and attach it to feature lines instead of alignments and profiles.
If I model a parking lot I use 3 feature lines. Edge of Pavement, Gutter, Top of Curb. Why can't I just use one feature line and have the curb and gutter assembly attached to it.
Why not ask for a curb and gutter object you can model? Then also have a pavement object that you can attach the curb to. Adjust the curb elevations, watch the pavement adjust. Adjust the pavement watch the curb adjust. We need new workflows, not incremental changes to our existing work flow. Afterall most of our workflows are still rooted in pen and paper, instead of taking advantage of our awsome computer processing we have today. All I'm saying is ditch the feature line and adjust the curb object directly. Even have it have transitions between curb heights, curb openings, curb ramps, sidewalks, retaining walls that all interact with each other. Including right angles.
If we continue to ask for incremental changes to our current workflows we won't get to better designs. Asking for how you would want to do it from scratch will probably give us a better product and user experience.