while not "fully adjustable" i grew to prefer using a sling for a bridge on my saddle. depending on how you loop it through your bridge loops you can set it in a few different configurations using a carabiner. this makes the bridge openable, and you no longer have to step through a bridge with muddy muck boots also. switching the configuration is as simple as going to my lineman for a minute, changing configuration and sitting back down, no extra parts or anything.
keep in mind with these photos, this is just for demonstration purpose, these are not the biners i use for hunting. crossloading on the carabiner in the first picture hasnt been an issue for me, when using proper size carabiners, but something you should be aware of