Brian
Whilst the concept has merit in practice not sure it will resolve the issue. In the deep distant past I tried this type of sling and found that other issues came to the fore eg wire strands started to break, wire was uncomfortable against the arm etc. Am sure you have tried to resolve the problem before exploring this option.
For information in my case I adjusted butt plate down thus lifting stock up, hand stop will need moving forward slightly. Also adopted a higher position by placing right elbow closer to right side.
I note most juniors shoot rifles that have a wood stock thus limiting amount of adjustment that can be made. Hence the options available to you maybe limited.
Nope do not have that sling went into bin moons ago.
Regards
Joe