Wow!! Scary stuff. My concern with cast aluminum has always been is the possibility of sudden failure. When a platform made of steel or aluminum tubing has been over stressed, you will usually see deformation in it which indicates that the material is yielding and if you continue to use it, it will likely fail. Cast aluminum will not deform if over stressed it just fails with no indication. Each of the cast fingers making up the platform can then become little knives with serrated ends that can open you up like a scalpel. Even though you are wearing a linemen's belt or tether, the one or two foot drop can be season ending if the jagged ends of the cast platform open up your legs. I'm not sure I will be able to get past that image and trust the flexing platform.
If I weighed 150# I probably wouldn't worry a bit. Weighing 250 and with heavy winter clothing, boots and gear even more and knowing that the test platform failed at less than 600# with a controlled load applied to it, I wonder what might happen if I put all of my weight on one corner of it...
There are hundreds of posts on this site about the Ropeman 1 having a rating of "only 15Kn" which equates to 1-1/2 tons. I would feel much better about using the Predator if it had a 5x safety factor instead of <2x it's rated capacity even if it weighed twice what it does now.