I can see rubber deadening the shock harmonics but if you drop the shaft tip first onto a hard surface, the shock harmonics should have little to do with the recoil distance.
Perhaps that’s a bad example due to Le Pros having a significant “your mileage may vary” factor to them. Dr Dave has a hardness chart that measures them to be quite soft. Pool Dawg has a hardness chart measuring them to be quite firm (more so if you don’t remove their initial factory coating). My personal experience with them has been on the soft / mushrooming side. But I do know others have experienced different.