if the point of the question is then to say why did Renault spend so much money on the suspension set up, the answer is because the car was desingned to be used on the track and the set up allowed for a much better control and progrssive feed back.
Damper fade will tend to only happen after a large number of high speed laps, or heavy use as in the Clio rally cars which is where the system has been taken from (Tarmac set up only)
its not the point, the point is Renault knew that this car would be a hit for track days, thats the reason they took the suspension settings from the Clio rally car in Tarmac guise, and adapted it for the Trophy.
The Clio sport range has been most popular in the UK more than any other country which they have been sold in. A large number of the owners have used the car on a track, and when investigating the best possible send of for the Clio sport The Trophy was the obvious option, track orrintated.
its not just rallying that the shocks are used they have been used in the VW Polo cup race seris and the Beetle series where the competitors have to use identical cars which tend to be stripped out road version with specific mods (beefing up components)
The sachs dampers have been specifically desgned around the clio to give the car one of the best handling cariteristics around.
I agree that many parts off rally cars are different mainly because of the job they have to do.