Even though I've always adhered to this advice and never let a tire shop lift my RR using a two post lift having changed the front axle on my P38 I'm no longer convinced its the issue its made out to be. I had to drop the axles down below the full extension of my koni gas shocks to remove the axle and kept an eye on the height sensors while doing it.
If you think about it logically, as long as the ignition is not turned on while the suspension is 'over-extended' the EAS has no way of knowing that the reading is out of spec so can't throw a hissy fit.
Someone made the point that it could be crap getting dragged from an unused part of the track to give a dodgy reading, this I would accept as potential problem but would be very short lived.
I reckon the issue has arisen where a guy leaves the ignition on to power the radio while working on the jeep and inadvertantly allowed the EAS to "see" an out of spec problem.
To my mind if you've got OEM shocks hanging the suspension off them should not be an issue. The P38 is supposed to able to avail of the full travel of its suspension while off road. There isn't going to be that much of a difference in radius arm drop between a cross axled rangie and an axle hanging from both shocks.
Just my tuppence worth.