Joe,
Most all listed or labeled equipment comes with instructions that are required to be followed, and include detailed guidelines to keep the products operational.
Only instructions that are part of the listing and labeling are required to be complied with by 110.3(B). If all manufacturer's instructions were required to be followed, then there would be no code compliant use for "classified" breakers. I have rarely seen "maintenance instructions" as part of the listing and labeling information. Yes, they are almost always included in the manufacturer's instructions, but not in the listing and labeling, and yes these maintenance rules should be followed, but I still see no NEC rule that requires this.
The switch in your last post certainly should be repaired or replaced, but it has already been installed, and was apparently in compliance at the time of installation. At this point, unless it is being replaced, it is outside the scope of the NEC.
Don
