Personally I don't like the reach and draw angle with a holster on the pack belt, it's too high and unnatural for me.I've got a drop leg, the issue I have with this is that the belt I wear to support this holster ends up affecting the muscles being used in carrying the pack, it's weird. I have my pack loaded all the time, 50-60 lbs I suppose, and I wear it around the house, or when I go out and work on the boat, truck etc... I always wear a gun too
Something with having that additional belt on with the drop leg made different muscles work.
This pack has a section on the hip belt that allows a paddle holster and I actually have a quick draw paddle holster on it now, but I don't want a holster on the pack for permanent use, too easy to set the pack down, go to take a leak, then realize you're without your gun.
I have a gunfighters inc kenai, and that works, you can move the gun wherever you want on the front of your body, shouldn't have an issue making it work with a bino rig, put it under the rig, below it, above it, off to one side, there's a solution for you in here somewhere.
Crazy potential solution... look at the fast draw cowboy rigs with the big 3"-4" wide belts, you generally wear them loose and lower, could likely sit below the pack waist belt and certainly allow quick access to the gun. Though in rough terrain you'd want something keeping that gun from falling out. This may just be the neatest rig if it were to work out.