Not really, I have not found that to be true at all and it definitely improves comfort on the primary. And I am not the only one who uses a swivel there. I am not DIR and I consider it only a minor violation of Hogness
. There is no need for a 90/110 swivel on the backup and have you tried putting one on the secondary? That would require going to a yet shorter hose to prevent pushing. Not sure that would work. I do have an Atomic "type" swivel that I have considered using on the primary but the 90/110 allows the regulator to sit centered in my mouth with no pushing. I think I could get away with a 20 inch hose on my secondary, especially with the braided hoses. I may try one there.
The picture was taken with an NA-6400 and a WWL lens at about 8 inches from my face. Wide angle, semi-fisheye lenses like the WWL distort the image and exaggerate distance, it is all much tighter than it appears in the photo and a G250 is a full size second stage but,
, they are not that big! The G250 on the necklace looks a lot smaller.
This photo taken with a Canon A570 and Inon WA lens circa 2008 or so in Destin, FLorida. Notice how the stiff rubber hoses and the lack of a swivel push/pull the primary sideways:
And notice the much better dynamic range of the APS-C sensor vs the point and shoot bitsy 1/2.8 sensor.
James