This is a technical limitation, because the preview can only show what is stored in the settings dialogue. The length and boundary shape aren't stored in the settings dialogue only in the element itself - like the polygon shape of a Slab.
EDIT: Ok, I see you meant the elevation. This support hasn't been added. The elevation I think currently only support doors/windows, and CW frames/panels components.
Some curtain wall do not appear correct.
Thank you for your questions!
First, unfortunately, at the moment it was not possible to show the elevation of the Curtain Wall in Schedules yet. There is an existing wish for this in our Wish List library already.
Second, regarding the wrong preview for Curtain Wall in schedule, unfortunately I was unable to reproduce this. Could you share with me a sample of your project for further investigation? Please let me know if you need a secure place to upload the file to.
Unable to show elevation of curtain wall in a schedule is ridiculous. So I have to create elevations and patch them into the schedule? And to have an unobstructed view of the curtain walls, they need to be on a separate layer because you can't selectively hide elements on the same layer if something is adjoining the curtain wall on the side.
I do like ArchiCAD for being systematic so I understand approach is not the Revit style where you can manually override anything (I find it very dangerous as a lot can be missed that way) but a property that would allow for show/hide would be amazingly useful.
Ability to have a completely invisible line for override or invisible pen available for all settings would be a dream come true.
No need to create separate layers. You can hide/show per element in 3D. Use parallel projection and look to perpendicular of clicked surface, and convert to 3D Document to generate individual CW elevation.