You can’t expect the 1.5" unstructured to perform as well as the 3" it just not heavy enough for your intended application. I used 1.5" aluminum Unistrut on my roof rack but all it does is support 2 solar panels and it is more than sufficient for that purpose.
You shouldn’t be sitting on the roof of your van no matter what. Van roofs are not designed for that purpose.
You shouldn’t be sitting on the roof of your van no matter what. Van roofs are not designed for that purpose.
