Are you saying you like the brand that specifically tells you to never mount a fire extinguisher or tank of any kind?
Or that you think any of these is not safe for that type weight in motion?
I'm a bit confused on your point. I get the part about moving weight and filling those racks up with hard and heavy then getting in an accident, something has to carry the load. I expect some people here could figure out what the stressed might be and where the failure would likely occur.
But the OB rack says flat out... don't do it... and one rack I saw, not sure the brand, was not even attached at the rear.
So are you saying the Toyota mount points being used are not going to carry the load under stress or that this specific one is weaker than others by design. To me it looks like it's mounted more securely than others I've seen so I can't quite understand what you are trying to get across.
I don't know who makes this one, but it's clearly going to be a problem.
https://www.youtube.com/watch?v=PGUxFQwrf6w