All the things that form the hook would have a lot of force on them.
I had the thought of a connection of the string on the back of the bow. So that the string forms a circle.
There are a few knots to do something like that. I use something like that for tents.
... You would not even need to knot them. The string can be a whole circle. When you want to shoot tbe bow you would have to bend it and put the string on. Strange but works. The thing is that the string would not stay on the back but slip to one side. Either you prevent it from doing that with a groove on the back (probably a bad idea) or you let it slip to one side what might need some adjustments in tillering ect.
I mean thats very strange but we are talking about make a "weird idea for a nock" working, right?