I'm gonna have to disagree here Kel....
Not being in LR with a QuadraTrac II is tantamount to having open diffs both side to side - as well as front to back. Not good on sand..... I prefer to at least lock the front to back torque balance at 50:50.
Just don't go so fast!
At Stockton (incredibly dry, fine sand) I run 12psi and LR on sand - always!
HR gets me bogged over the undulations as the weight shifts dramatically from side to side, and the open diffs have a field day.
Maybe it totally depends on the sand that you, in your area, normally drive on. I believe that the Stockton sand is fairly unique.....
I found the sand on Fraser Island to be rock-hard in comparison. 2WD would have got me up and down the coast road all day. Different kettle of fish at Stockton...
In my Patrol (with that 1st-class rear limo) I also ran 33-35" tyres and 5-10psi - in low range too. Admitedly, the Pootrol ran a petrol motor and needed to rev like crazy on soft sand. The diesel finds the going a little easier..... but not much.