I am still having this same problem. Both in 6.3 and 7.1.
I have created a curtain wall panel which I have added to a divided surface in the Conceptual Massing Environment. I want to allow the thickness of the panels to respond to their distance to a certain point (An attractor point). I can select the panel family through “Family Types,” and I can control the value of the thickness when I have it set as a Type parameter, but it won’t show up once it is changed to an Instance parameter (It won’t show up in the “Get Family Parameter” dropdown, and when I use “Element.SetParameterByName” and enter “Thickness” in a “String,” it says there is “no parameter found by that name”).
I want to have this set as an Instance parameter since I want each panel’s thickness to be unique. Interestingly, when I tried to set the Type parameter to different values in 6.3, Dynamo would crash (I assume because it wanted all values to be the same, and I was giving it a list of values, but in 7.1 it will simply give all panels one value).
Any help would be much appreciated!