I don't think so, A novice wouldn't have used a sled mount. He figured telling somebody to lug two cinderblocks up some stairs is better than saying six.
I haven't responded to this post further, since I wanted tp provide others with the opportunity to do so.
A custom mount would have been in order, but I am sure that the installer had neither the time, the resources or the tools to design, build and install one.
First, the rails of the balcony could easily exceed the load requirements for mounting the 32 pound static load of the AT9 dish. Building code and engineering standards require a minimum of the railing's ability to retain a dynamic load of 250 pounds, with some codes requiring a load retention requirement of 600 pounds or more, due to the increasing obesity of the population.
The solution for the original poster's situation lies in increasing the rigidity of the mount and it's inertia to prevent displacement.
He needs to use at least six (6) 8x16x 4 inch concrete cap blocks laid down on the side to affect the lowest center of mass and to achieve the highest friction between the angle iron mount and the concrete floor of the balcony.
Then, to make the mounting as rigid as possible, you'd need two "monopoles" between the neck of the mounting arm and two of the balcony rails.
It is unexcusable for the installer to use a flat cable, when he has been approved to drill a through hole in the wall. Since all cables in electric boxes enter and exit from the top, the safest place is drill is always 2-3 inches to the side.