Bro, 3 pictures before this.. I have a wedge post. I thought this idea was cool, so I figured I'd try it. It works really good, and is overall lighter than a wedge post.
It doesn't really weaken anything that much. The tubing was surprisingly thick. I only payed $30 for this frame, not much of a loss if anything happens. It wouldn't be a pain in my ass if I bought a new frame, more-so a benefit.
Does not actually weaken the frame in anyway as the only force on this area would be on the bolt itself... and have you ever seen a seat tube crack and I'm not talking the weld on the seat tube but the tube itself?
definitely doesn't make the frame any weaker. I find it funny that you chopped the seattube super short and made a "custom" seat clamp, yet you don't run your seat slammed.
I actually have two holes drilled in my post, one in this height and one to slam it, haha. I just like how much cleaner it looks compared to a traditional clamp.