"So for the RV crowd with seemingly endless amounts of time to think about maintenance, adjusting the valves would be a harmless excersize - done correctly."
I think I'm one of that crowd. Don't know about endless time for an RV, but I do know that preventative maintenance, which is not limited to the required maintenance, avoids a lot of problems for an owner and reduces the likelihood of a failed trip.
There are classes on preventative maintenance and generators. But, you have to be a diehard DIY to take these classes like I did instead of having fun and staying on the road.
I would have to look, but I don't remember reading about adjusting the valves as part of the maintenance in the generator course.
Unfortunately, my wife has her list of endless cooking requests for me today. My wife refused to cook when she figured out I can make restaurant quality or better meals. However, she does help with the preparation and cleanup.