A similar issue revolves around "demonstrated" crosswind values published in AFM's that sometimes includes the statement "not considered a limitation". If the aircraft has a demonstrated crosswind value of 15kts (with the statement that this value is not considered a limitation) & you run off the runway & severely damage the aircraft, where do you stand from an insurance perspective? If the crosswind was 17kts, you may be OK, but if it was 30kts, you may not be. The only way you can be reasonably certain of insurance coverage is to stick with the manufacturer's demonstrated values in my opinion, but this argument has been ongoing for a long time...