I've recently fitted a Jetzed moderator and find that , at 5'9", it definitely catches on tufts etc when carried muzzle down.
Am also trying an American 'Nimrod' pack, which has a scabard mounted cross ways left hip to right shoulder. I don't think they are designed with a moderator and a Harris bipod in mind, because the rifle is a tight fit. Its a bit fiddly to continually get in and out. However, it could work well on the hill when you are only likely to take it out once after a couple of hours approach work.