Yep. My left shoulder was dislocated about 25 years ago playing football. I rehabbed the heck out of it. For years and years. I still do it today in order to keep it equal in strength and stability. And, on my Kifaru frames, the harness if about an inch longer on that side.
With that said, the harness on my SO doesn’t allow that. But, the way the harness is made, I don’t notice on that pack except when tightened down. The buckle on my left shoulder strap doesn’t wrap as far around my shoulder as the right.
It’s no problem on either setup. And, my guess is if more people were open to the fact we likely aren’t symmetrical, there’s be more people with differing adjustments.