I've used many cargo racks. Most are bigger and stronger than I need.
I decided to build one from some parts left over from a shelving unit.
My fender struts are very strong, so I can support my mini rack on them.
First pic - Mini rack is folded and stowed.
2nd pic - Cross brace is unfolded for stability.
3rd pic - Rack trunk is attached to the mini rack and ready for cargo.
I tested this setup with six cans of soup on board with no problems.