I must say I'm not sure how four legs will work within the UK market bearing in mind the load point when stood or leaning forwards is roughly where the seat and platform meet when the platform is extended. This is usually where the middle legs are placed to provide support.
@MKQuattroUK is there a max user weight set for the box?
I'm a mere lightweight compared to some at 15 stone (95kg) and wouldn't want to put all my weight on that point unsupported.
Also, the "no-welding patented technique", I know welds can sometimes break but is there a reason why the manufacturer has decided to use what look like plastic jointing blocks and brackets rather than welds?