Not sure about the reason the shop is recommending not installing but there potentially is a reason you might want to go with something along the lines of a Safe-T-Plus: The steering damper you mention is only going to be strong enough to handle minor stresses on the steering and will be of little assistance in situations where there is a severe impact on one of the steering wheels, such as a blowout. I had one of the steering dampers on my 23' class C and it provided nominal steering support even on normal road conditions. The Safe-T-Plus, and similar like-sized units, are capable of handling a coach of our size and weight and you will see the assistance even in non-tire blow out situations: such as, uneven road beds, passing semis, elevated wind hitting one side of the coach, etc.
2007 Newmar Baystar; 3201; miniature schnauzers and labradoodle. SumoSprings Front; Safe-T-Plus;2016 Fiat 500; Roadmaster Falcon 2;Demco SBS DUO Braking System;TST 507;Bilstein shocks