When a layer in a PDF has its visibility toggled off, it would be great if the legend item associated with it could also be turned off.
The use case for this is that if a Layered PDF is provided to show property owners whether their land parcel is affected by one of several pieces of legislation, and they turn off a legislative layer to get a better look at what is there, then they could print from the PDF a map showing the legislative layer in the legend and no features from it affecting their property. I would hope such a map would not find its way into court.
I think that if a layer is turned off in a PDF then all legend items linked to it in the map from which it is exported should also be turned off.