One thought that I had is a landing net retractor or possibly one of the magnetic net holders for fly fishing. Not something I think I would use, but just an idea. I keep mine in my pack hip belt pouch.
fhf here as well. I keep my Leica 1600 in a pouch on my bino harness along with the tether cord and it is completely out of the way, but I can get too it very easily and quickly. Excellent setup.
I use a fhf Bino harness and just run my vortex ranger 1000 in its factory pouch on one of the straps that goes around my chest. For added security I use the neck lanyard. So neck lanyard around neck and then rf in pouch on Bino harness strap. So I can drop pack no problem and drop the rf as its around my neck as well
I predominately bow hunt. I either have a bikini frame or spike camp pack while hunting. Regardless, my system works the same. I keep my range finder in a small belt pouch on my right hand side, attached to the belt loops (I am right handed). It's right there, out of the way, easily accessed on a stalk, etc. Seems to me like the small belt pouch was perfectly designed for a rangefinder.