Different cross section shapes in a truss

Hi everyone,

I've drawn a N truss in Grasshopper and analyzed with Karamba. For optimizing, I've used the component Cross Section Optimizer. At first, I used List item with the component crosssec. range selector to select a family of cross sections. This family of HEB (for example) is then used for the whole structure. The truss is seperated in top chord, bottom chord, diagonals and verticals and I want every part to be a different family, like HEB for top and bottom and rectangels for the diagonals and verticals.

I tried this by putting in the index te numbers of the familys (as they are in the cross section selector) in the input index from the component List item. Then I made a second panel with the names of the truss components (top, bottom etc.) and put this in the input ElementIds in component cross section optimizer. For clarity I attached a .jpg file from the screenshot, named List item.jpg. This created errors that not all cross sections are used and that the crosssections need to be bigger than their biggest family member. Then I tried to do it with 4 components of cross section optimizers and all of them connecting with again 4 components of cross section range selectors, and this also didn't work. Last option was to seperate all of the truss components from the beginning by creating 4 assemble models but this was really complicated because I had to add al the supports on al the beams etc,. I don't know what else I can do and I hope you guys can help me. I've also attached the grasshopper file. Thank you in advance! 

Kind regards