Look up Lone Wolf and lawsuits over stand failures. I have 2 Lone Wolf hang on stands, and while I am fairly confident they are safe and strong, I certainly understand that things do break, and it's really bad when they break when you are more than 10' up in the air.
I just made a saddle platform out of a Lone Wolf replacement seat. While it works to stand on, I am not totally happy with it because it kicks out when you apply side pressure. For that reason, I ordered a Trophyline platform. Comparing the two castings, the Trophyline platform is easily thicker, and the webs are deeper. Also the webs that the attachment bolt goes through are bigger than the Lone Wolf webs. I will make some adjustments to my homemade platform to improve its stability, and I will probably keep it as a backup.