I notice the factory applies this already? My 2010 Roadster rebound springs are un-compressed in rest (can be turned by hand).
I don't think that is usual. My 2012 Plus 4 was certainly not like that. I suspect either someone has changed the springs or that a weaker set of top springs were installed. Personally I believe the fitting of the correct springs for any given model may have been a bit haphazard. Mine were changed under warranty because the wrong springs were fitted. I eventually fitted Suplex.