If I was working in the dealership that looks after these machines I would be telling the customers that upgrades were available, but I'm not and my suspicion is that they won't do anything until they are asked to. Be aware that the upgrades are not mandatory, simply improvements in machine systems control that can majorly benefit both the operator and/or machine reliability. It's a really surprising position for the dealer to take TBH because if they have a contract to look after the machines you would think that they'd be trying to show how customer-focused they were by doing stuff like this without waiting for the customer to ask. To upgrade 4 machines would most likely take about 4 hours in total, compared to what they are coining looking after the fleet it's nothing IMHO, and excellent PR for them.....
What escaped many people, including the factory, is that when the engines using the the graders changed from 3304/3306/3406 to the C-series a lot of inherent engine braking went with it. The rotating mass of the new engines is nothing like what the old ones had and so you can't depend on simply taking your foot off the throttle like you could on an H seires machine. It's actually interesting to compare the operator manuals for the H & M Series. For roading an H Series the manual tells you to select the same gear to descend a given gradient as the machine is capable of climbing the same gradient, for an M Series the manual tells you to select ONE GEAR LOWER than whatever gear the machine will climb the same gradient.
We saw this initially when the 16H II (with the 3196 engine) first came out. Our customers started burning brakes up like it was going out of fashion where it was never a problem with the former model equipped with a 3406. It took us a while to twig what was going on; we approached Cat about a Jake Brake installation, only to be told that no engine software was available to support the installation of a brake. So we did it anyway using the brake installation from an on-highway engine and by installing a microswitch under the throttle pedal and a latching relay, so that if the throttle pedal was touched when the brake was operating it immediately dropped out. When the 16M first came on the market a Jake Brake was optional, it took about a year for it to become part of the standard machine, and every early machine sold without one qualified for an upgrade to retrofit one. What we do to stop our operators gassing the machines too much is to limit the transmission to 6 forward speeds only - our brakes live forever .......