I have found a product that may suit better
Quick Fist Rubber Clamps for shovels etc many sizes
you could fasten to your canopy roof
And pack it out with some pool noodle if needed
I use a few Railblaza products on my kayaks and tinny.. what might be of use could be Railblaza Rodrak Pole holder or G-hold... Ram mounts or Scotty mounts might do someting similar. Usually available at all good chandlery stores