I have been looking at binocular harnesses ranging from $10-110 dollar options. From the very simple to semi custom made in the USA.

Ended up going with two $.30 keychain rings and 7'4" of 550cord.
I see it being all day comfortable for all but the heaviest of binoculars.

Here is the video.

Not for me... I see it being very uncomfortable due to a string hanging on your shoulders and the binos not being secured against your chest. Plus, the zero protection for your glass. If cleanliness of your binos is not an issue, call camofire and order the S4 bino harness. If ya want comfy,clean, and secure, spend money on the Kuiu or Alaska guide harness. I have the kuiu and it did very well elk hunting. If ya just walking to a tree or shooting house I guess the paracord will do.

If I'm dropping a sizable amount it would be the Oregon Packworkd Binobro or FNF harness

Out of those 2, I would go FHF. I almost got one but didn't want the mesh backing. I have one similar to the oregon one but, I don't care for it so, it's on my junker binos in my work truck.

This is essentially what I made, but out of paracord

Will definitely be lightweight.

They are retained very nicely for such a simple setup.