Hi Autodesk
The Detail Level is a great tool to show the same object in different Detail Levels. But it seems that this is not possible with mullion profiles.
The only way is to only create the curtain wall and setup with grid lines and add the mullions to the curtain wall later on..., but sometimes it could be nice to scale down the graphics, so the gridlines is visible but not the mullions, later on in the project.
This could also be a great tool when reusing the same model to Autodesk CFD or at the end delivery of the project so it not to heavy for the FM. Therefor can this wish be time consuming on projects.
This function is on many other families but not supported in profile families...
It is possible to choose the lines in the family at set them not to be shown in Coarse, but is has no effect in the project.