I've had a couple of these exhaust jacks over the years. Great bit of equipment for lifting in sand, as an alternative to something like MaxTrax. Generally used at the side of the vehicle for raising two tyres at a time to then fill the holes created to build traction, then deflate and do the same to the other side. I have used this under the differentials on an old hilux to lift the entire rear of the vehicle (plus the contents of the tray) and then push the vehicle sideways to get the wheels out of a set of ruts. Whilst this is not the 'best' use for the device, and they have changed over the years (they used to be just a bag with two pieces of plastic similar to what you find in the bottom of a Woolies shopping bag for heat protection - now they have that protection built in and are less of a bag and more of an accordion in their use) it has gotten me our of trouble several times in minutes, where otherwise I'd have been stuck for a lot longer.
One bad experience with one of them though. First time out of the bag, was testing a new exhaust nozzle design (can't remember manufacturer sorry) and the bag inflated fine, lifted 3t of Landrover Disco 2, then promptly split (22" split on the measure) and dropped the vehicle from about 10" height and frightened the stink out of two people camping nearby (loud bang).
I think for the KL, and its limited lifting points, a Hi-Lift jack may be wasted in preference for an air jack, or a set of MaxTrax.
Below is a photo of the offending exhaust jack (post-explosion). Test your equipment in neutral territory before you need it out bush.