All in the geometry, the distance below the tow ball connection point is for the chains allows a horizontal tension to be turned into a vertical lift via rotation. HR systems use rotation as well as vertical lift when lifting the bars.
I did not note the lifting capacity (distance) for the system, but I would think that the system would not lift 100mm. I would think that air bags or heavy duty springs would be needed as the tow vehicle should only move a small amount. This would allow the system to shift the weight to the front wheels of the tow vehicle with minimal height adjustment.
Removing the bottom plate without untensioning may be possible by jacking the tow hitch (with caravan connected using jockey wheel) the same distance again as the distance the system lifted the van in the first place. For the 100mm lift this would mean raising it again by 100mm. IMHO you would need to loosen the nuts, but you would place the jockey wheel on and take the weight of the van (and a bit more) to make it easier. Once set up I would do the same for setting up. In this situation you might find that with the jockey wheel attached and raised to the right height you do not have to get the system to lig the van 100mm.
This then asks the question would this system interfere with the jockey wheel the same as the HR system?
My issue would be the brackets on the caravan for the tensioning system. On HR (and others) this is a downward force with a small amount of veritical (this is why the HR system sits on top and can use a single nut to lock on). For this system it is very much a horizontal force that will try to rotate or move the bracket along the A frame. If it does this (moves the bracket) the system will stop working on that side and place more load on the other side.
. In saying that I'm open to listening to anyone who can explain the physics of the system, specifically how it loads up the vehicle and trailer.