I don't think there is a way to assign different property objects (PO) to different parts of a Custom Profile. If there is I would like to know, but it is basically assigning a PO to the whole thing in the wall tool, or via ID. This is a limitation with Custom Profiles.. calculation that is. This is the reason I use separate composites for the wall and the footing. I keep quite a few with different PO assigned to the composites vis the fill. I suppose you could figure out a PO in your situation as long as the wall stays the same height, but the multipliers would be challenging, to say the least.

Can anyone tell me if anything has changed from Rick's remarks that there is no "way to assign different property objects (PO) to different parts of a Custom Profile"?
We are unable to get correct area quantities of the external face of complex profile brick veneer walls. The calculation of the area of the external brick wall includes the height of the internal stud wall (usually higher). The same problem occurs with the internal stud wall of the same complex profile. Can anyone suggest a fix? To further clarify... in a typical situation, the brick veneer is 155mm below the bottom plate of the internal stud. The internal stud wall is higher than the external brick by 300mm plus ( depending on various conditions). It seems that any Surface A and Surface B calculation can only recognise the overall ht. of the wall (bttm of brick to top of stud) and not each wall composite individually.
For Graphisoft... if a calculation can be made for the thickness of each fill in the complex profile, why can't we also get a measure for the height of each fill?