Not entirely Jimny related....

Just watching some random videos and one showed a small floor jack like about a 2 tonnes size. What was special was that the wheels had been removed and the entire base was closed in with a thick piece of aluminium tread plate with the treads down to offer grip and load spreading on a loose surface. Obviously the pad moves in an arc and the base can't slide so it will move the vehicle as it rises which is less preferred than a straight lift. But other than that is this something we might consider suicidal to use in much the same category as a high lift jack or is it something that might have a place in the back of the car for a day out on the lanes or play site? 

This One?

Saw that last week myself.

Its just as dangerous as any other lifting or recovery equipment, its how it's used rather than the device itself. Now that as a statement has just opened up a range of activities from perfectly safe to suicidal. So many factors, so many opinions, this is just mine
So it has a place, just use it safely.
I like it as a DIY solution if you want one.
 

It wasn't that particular one but they share a common ancestor. Safety wise I agree it's entirely down to you as the use to not do anything you will potentially live long enough to regret. Using what is basically a ski on anything like an incline without adequate roll away prevention is just one example of Darwinism in action and the list of other options is endless, I get that. I think I was more wanting to consider the principle in case it was a too good to be true idea given the date today, and essentially it seems sound, I think?

In principal it looks like a good idea if you favour the trolley jack away from paved or concrete surfaces.
its going to work better than wheels on any surface that's not solid, spreading the load over a larger area. Its possibly even easier to slide underneath, and may even slide with the arc as it lifts. This does depend upon the surface it's deployed and how much grip the vehicle has on terra firma.
I can see the principal for it's existence, so even if it is an April Fool, under certain circumstances it's a good idea.

But then you can sort of achieve the same with some sand boards / and a normal trolly jack. 

Using a normal trolley jack on a piece of 18mm plywood would be better in every situation I can think of.