Groups seem to be almost there.

When I create a group and place two copies, I actually get multiple items, as I can actually remove any one from just one instance of the group. MIn other words, a group made up of four walls, placed twice with a common wall overlapping actually results in 8 wall objects in the database, with one of the overlapping simple Excluded From instance. Cool, until you try to take advantage in a Design option.
This is a four story building and I want to look at two design schemes, one with a brick facing on the first floor, and the rest get a stucco or whatever, creating a "heavy base" kind of look. The other is stucco on the first three floors, and a metal siding on just the top floor, creating a "light top" look. The finish expression is not really tied to the building form yet, so I want to be able to flex the walls and have the two skin expressions continue to work.
What I tried was this. I made an exterior envelope of simple generic walls, grouped it, and placed the group in two design options. Because the south wall in Design Option 1 is in theory a separate object from the south wall in design option two, I expected to be able to split face in Option 1 at the first floor and paint in some materials, and split face at the 3rd floor on option 2. But alas, Groups and Design options don't play well at all. I have to have two un-grouped sets of exterior walls in order to do separate split faces, and then I have to track changes in both, I don't get any Group value.
So,m it seems to me that Groups and Design options should work together, so I can indeed have one group, that I can adjust spatially, but two instances of the walls, one in each Design option, that I can then independently Split Face.

This would be great for Interiors as well, where the group is placed in the Primary Option and populates the main set, and again in a Design option so the paint scheme can be worked on. If the walls in the group move, the Architectural set stays up to date, and the Interiors "option" also stays up to date spatially, along with having the split faces and painted in colors for presentations.

Best,
Gordon