Must admit we have a similar concern with respect to the caravan tipping, so one of us walks beside hitch ready to put extra weight on it if required. I also leave the rear steadies down slightly, although that may simply be a panacea.
Iain
Have to say the hill I'm on is quite steep. Returning with a new empty van the hitch started to rise as soon as disengaged from the ball. It only required a hand on the hitch to hold it down and all went well. Now with around 90 kg nose weight there's never any issue.
Just one last point that might be useful.
I've sometimes had difficulty disengaging the hitch from the ball. This is because the hitch is fully extended and there will be positive pressure against the pads. My procedure now is firstly engage hand brake, secondly engage mover and remove breakaway cable, thirdly take off the hand brake and lastly move the van slightly towards the car to negate the grip of the pads. (This proves that the movers are engaged of course).
Then it's simply a matter of winding the jockey wheel to disengage and take the van into the drive and to its storage position.
As an aside. Whilst I had a lighter van years ago, without movers and frankly had no real problems, it was my wife who insisted we had movers fitted to our first Lunar Clubman. How right she was. Apart from getting the van in and out of the drive - impossible by simply tugging (and arguably dangerous to health), I have absolutely no hesitation in using the movers to set the van in its final position on site.
Ours is a single axle and fitting the security would involve "messing about reversing a bit etc. etc." especially when ramps are needed. Reversing onto the pitch with car I do if I can see properly - preferable not blindside - but always fine tune with the movers.
Since we tour in Europe quite a bit we are used to some sites having small pitches and bends on the road requiring unhitching and there the movers come into their own. Years ago fellow Europeans would stand and stare to see the van moving all by itself. Now that's rare since most are familiar with them.
Soooooooooo - apologies for rambling on but yes a mover will control the can on a slope if properly engaged and yes, on a steep hill the hitch can raise and the van try to tip backwards.
Both concerns are easily negated as others have said on the thread.