I love the notion that an LR4 can be "lifted" in under an hour by replacing the height sensor linkages.
I don't know if this is an issue for the LR4 or not: I remember reading about a couple of instances with Range Rover Classics and airbag failure. On these occasions, the vehicle was on a steep incline, and on one wheel the suspension was at maximum travel. The suspension shifted so that the top and bottom of the airbag were out of alignment, and the airbag collapsed sideways. After that it could not compress. I've seen a picture of this, but have not been able to find it.

Needless to say, extricating the truck from that predicament was problematic. As I said, I don't know if this issue applies to the LR4 or not. I just thought you should be aware of it.
My recommendation is to thoroughly test your truck with Johnson Rods installed in a location where recovery is relatively easy.