If your 475 naked...You've pushed the safe working load of even the 2 man. Is that the end of it? Heck no! Either build your own stronger or add to the 2 man to make it stronger. Keep in mind you have to get the thing out there. Even if you don't add some steel to the thing, add plenty more ratchet straps. Some of my stands have 3 times the straps that came with it. Kind of hard for a stand to fail if it has to additional straps as back up.

Maybe a box blind would be better. I"ve never looked into the ratings of them.

I've heard stands break at 2x's the max load, however the rule that I know of in construction is always 3x's. In other words if something being tested breaks at 3000 lbs. the NBC will give it a max load rating of 1000.