The "correct way" depends on the conditions. I usually just use 4 high with the center unlocked in most on road snow driving when you will be turning a lot or going from a fresh plowed road to an unplowed side street back to a plowed section you get the idea. The center diff lock is for when you need more traction and less traction control interference. You should never use the diff lock unless there is sufficient snow to let the tires slide when cornering because you will create the driveline binding just like a normal 4wd vehice.
So 4 hi center unlocked is like all wheel drive, you could in theory put it in 4 hi and drive it like that for the life of the truck in any conditions dry or wet whatever.
push that diff lock button and its the same as the 4 wd in an old pickup truck, for use only in the dirt or deeper snow. If you find that the snow you are driving in is causing the throttle to cut back to prevent tire spin its OK to lock that center diff, in the highway or city it doesn't atter as long as the surface will allow tire slippage. The VSC turns off when you push the diff lock button. My truck has been in 4 hi center unlocked since 3 weeks ago because of ice and snow in some places but not in others.
As far as overheating the system they are referring to the atrac system which sounds like your ABS system going while you are accelerating (because it is)ATRAC applies the brake to a spinning wheel to direct tourqe to the wheel that has traction , so its like a limited slip system that uses the brakes instead of clutches in the differential. It works so well that the new Jeep Wrangler JK copied it . Some people have claimed to have overheated the system (probably wheeling hard or doing mud donuts for hours) but I abuse it and never had it overheat on me. The ATRAC actually works very well and the only time I can see it overheating is from excessive use such as driving through very deep snow for hours or trying to free yourself from being stuck for an extended time. In both these cases, If the noise from the ABS is constant its a good indicator that you need the extra tourqe / traction the center diff lock offers. just push it, no need to stop the truck. I think it should engage as long as you are going under 35 mph
