My canopy has two 4x4 steel square tubes under my canopy running the length of the UNDERside of the canopy to the front of the tractor. Plenty of support and protection.
4x4 steel tubs... that sounds pretty heavy duty! The tubes run all the way to the front of the tractor? Do you have a cage around you?
My canopy has angle iron bracing that runs the length of the canopy. I don't know how much strength and support it would give on a 360 degree rollover, like down an embankment.