Hi Brendan
To achive a split ceiling at different heights, i would advise that your create your own ceiling out of a *box from advanced graphics. The *box can be fully manipulated.
Also i would stick to the two individual walls, you can select multiple walls to be displayed in one elevation view by left clicking on the first wall and then right clicking to pick up a secondry wall in your navigation pallette.
If you would like further assistance with this, please conact the 2020 Fusion support team on 01233 635 533.
Thanks