My thought was to adapt this concept with folding legs, positive locks for leg height, and an adjustable, lightweight platform---perhaps an aluminum or steel mesh. I proceeded as far as preliminary patent work on the leg lock we came up with. Nobody wanted to pursue things further because of liability issues.
The platform shown was actually made by a friend since I was swamped. He really overbuilt the thing to the point it was very heavy. You get the idea though. I usually left them behind for clients since none every fit the risers of other projects exactly. They used them for changing light bulbs and things but assembled they take up space.