I'm not an engineer but that does not look correct. The tubing isn't designed to be pulled outwards and twisted. Versa buttons work by having pressure pull the strap INTO the the square tubing. I believe your design is applying shearing forces on tubing that it's not designed for.
Maybe someone else can weigh-in, or maybe I'm wrong? Just don't want anyone getting injured.
Edit: I do see where the bolt is going through two layers of tubing. But I'm not sure that helps.