1. This is almost exclusive to sustained free hangs. Bouncing against a wall or otherwise working your thigh muscles circulates blood with minimal effort, so standard climbing circumstances raise the safe time - potentially by hours. (Notably, Alpine climbing guides and specifically Alpine rescue guides do cover this syndrome in case someone falls and hangs while awaiting aid.)
2. OSHA-style harnesses are over-the-shoulder devices anchored between the shoulderblades. Many don't even have waistbands, just leg and armpit straps. That's useful for unpredictable falls, but it's the worst possible configuration for suspension trauma. Your legs hang straight down and the straps pull up at the edge of your groin, cutting off blood flow. Even hanging free, the climbing harness posture (elevated legs, pressure on hamstrings) is much safer.
3. Safety harnesses are mostly cheap and ill-fitting because you're not expected to hang in them; they're the same unpadded straps you get on the worst climbing gym rental harnesses. The time to initial risk apparently varies a lot with harness fit and padding, so comfy climbing gear is also much safer.
The ad below has a good visualization of the difference; it's from a company selling OSHA-compatible harnesses which pull you into a climber-like sitting position for exactly this reason.
https://www.rocorescue.com/ALL%20BLOG%20IMAGES/FreedomHarnes...
*: Prevention: when tied in you can't make it to a place you can fall such as a system that prevents you from getting within a few feet of a roof
Edit: the link you provide seems to be a lightweight fall protection harness and certainly one I'd like using as I prefer a lighter harness when working at height because it means less fatigue and less chance of a mistake leading to a fall.
Where this starts to really matter though, is in the event of an accident, particularly if you're above, and belaying a second, and the second is hit by a rock or something and falls unconcious. In this case, you often can't easily lower them, especially if you're more than 60 meters off the deck; you usually can't raise them unaided either, unless you're unhumanly strong. Setting up a z-pully in a timely manner, and hauling the second up is the best option.
Unfortunatly, these sort of skills are not often practiced in the climbing community.
Edit: also, I think it's less of a practical issue in a climbing harness, unless you also have a chest harness on, or a full body, which is pretty uncommon.
1. You probably don't have time. As the article says, you have less than 14 minutes. If the climber isn't within view, you may not even realise they are unconscious for a few minutes, perhaps thinking they just can't hear you.
2. If you don't have efficient pulleys, friction will be a major issue. Hauling a person up a long pitch on a Z drag is going to be a challenge. More mechanical advantage would just add more friction and time.
3. Raising the climb could cause them injury, or make their injuries worse, and could potentially kill them. Their body or the gear attached to it is likely to jam against something or snag on the way up unless it is a completely clear path.
Another option in that scenario is going down to the injured climber after escaping the belay. If you have enough rope out of the system, you can abseil down. Otherwise, you will need to descend the taut rope down to the hanging climber.
From there, I suppose you would need to manipulate their body to get blood flowing.
...and that is only the first step of the rescue! I hope I never have to face such a scenario.
Cavers will spend a long time hanging in space on rope when climbing out of deep pits (over 100 meters / 300 ft) with single rope technique. That doesn't lead to harness hang, because you are engaged in aerobic activity with your legs.
I cannot speak to any differences between climbing harnesses and safety harnesses.
Even for safety-gear falls, suspension trauma is somewhat overhyped for "slip and your harness catches you" accidents. The natural reactions - fidget, adjust for comfort, move your legs if they feel tingly - increase the safe time a great deal, so the main risk is falling into a hard-to-recover spot and getting tired.
That said, construction incidents are far more likely than climbing falls to be worst-case events: a substantial fall paired with injury or unconsciousness. When that happens, the impact pulls the harness tight and the victim doesn't adjust it or otherwise move around at all. That's where the stats about trauma starting in minutes enter the picture.
After my comment I did some more searching and found plenty of discussion of harness hang syndrome in the context of rescuing an incapacitated climber though.
I think I've only heard of a single accident when this has happened and involved death, though.
(hint: put it below or you could get stuck if you can't escape the prusik)
But even during super long belays, it's unlikely for the belayer to be motionless for even ten minutes.
But you're right, the weight distribution isn't really what matters in this case.