Nice little stand.

One suggestion when dealing with screw interference. If you use the inside tee slots to slide your bolt heads into for the cross members you can tighten them down with an Allen wrench Ran all the way through the extrusion where the bolts would have gone. Then you assemble the other members.

I like that you demonstrated the stiffness issue extrusion have it is one of the reasons I hate extrusions for critical machine parts. This however is a perfect application for extrusions.