A decent serviced pitch should require minimal setting up anyway. But for those who make more use of basic pitches with variable layouts simple and easy is a benefit. Particularly, if, like us you use the caravans shower and having good drainage is then a definite advantage.
I did mention that it also suited sites which allowed drainage into a hedge or ditch.
Genuinely sorry now that I tried to make a suggestion that might be of help to some.
John
......well I liked the idea John.
Made my own version from bits I already had.....cost me nothing and minimal extra weight.
No chance of waste water backing up into the caravan on awkward draining pitches.