We want to be able to break the pattern of curtain wall grids.
For instance, we crate a curtain wall with a 2.0m vertical grid pattern. At a certain place in that curtain wall, we need to place a 1.0m width door, and continue with the 2.0m vertical grid pattern. The only way to model such a curtain wall is to place all grids manually. For a long wall with many grids, it can takes a long time, and it's not automatic at all.