PRAMETRIC TRUSS 3D How can obtain a variable section?

Hi,

How can you see in the screenshot i create (with a tutorial en youtube) a 3d parametric truss, now, my question is, can i have a variable rectangular section? and if the answer of my question is yes, how can i do this? 

I solve that with force brute method :D with list item for each rectangle and scale each of them with different slider number (and even the planar plane of rectangle for scale it in the same plane).

but how can i repeat the scale process with a variable factor scale? 

In the first Screenshot have a parametric truss along a curve 

in the second Screenshot its how i can solve (with "brute force") the variable section. 

Thank in advance!