I can only speak to the rear tire change, but if you put the stock jack under the jack pad that is under the rear axle, I can see no reason why the jack won't lift the truck high enough to change a stock tire. Mine had PLENTY of raise to it to do this. All I can think of is either a) you put it in the wrong place or b) you have the wrong jack
And what's all this about giving the jack a workout? mine went up without any problem. Turned real easy, didn't heat up, or anything else. With a near 50/50 weight distribution, regardless of whether you are changing a tire at front or rear, what is the max actually being lifted? Somewhere between 1/4 to 1/3 of the truck's weight maybe? What's the big deal?
I'm certainly not trying to be argumentative here, and I'd love to have a big heavy duty floor jack for emergencies. But for the slim chance I'm going to have a flat, I'm not going to carry one around in the truck all of the time. Just my opinion