The 550 cord wrapped around the front sight is probably a good idea. Like mentioned earlier, if Israel uses it in front line conditions where they are, it is obviously fine for the rest of us. They are quiet and inexpensive, just not easy to remove like a QD or detachable swivel when you want to clean or store your rifle.
Since you made the coat hanger front sight sling loop, you reminded me of something I saw year ago in an arms room. It was a triangular ring of thin steel wire. It formed a triangular split ring, and the short leg of the triangle was wide enough for a standard rifle sling. It was hooked into the front sight tower, and the sling attached to it. It was about 1.25" wide and 2" tall. It was not as quiet as a 550 sling, but at least had a metal wire loop around the sight tower so even high heat was no problem. I never saw another one, but you could probably bend one up easily enough in 5 minutes. It looked like a decent sling attachment to me at the time.