Here's an update to this little project. Overall, it worked. I tried to beef everything up to keep the square tubing from warbling out the hole. The screw itself never bent, nor did the tubing warble, but the stainless spacer(smaller one) on the screw mushroomed.
Keep in mind, I only got three sits using this setup, so in my opinion, that's pretty light usage. But I will say, one sit I was using the double step setup as my platform...and I'm 250lbs. So take that however you want.
I still feel this could work, as long as the big spacer is used inside the tubing, and the thicker grade 8 washers are used. If a guy could find the smaller spacer in something grade 8 as well I bet it would work.
I ended up disassembling the whole thing to get the extra step back, and made a 4th stick. I do still think single steps are a pain in the ass, but for now I'll roll with it. I made my 4th stick, and added eastern woods cable aiders. Maybe next year I'll add double steps...at least to the top step.