I agree that K&B's description of the term four cycling appears to be different that other (most?) people's use of the word. However, I don't see it as very relevant, because the instructions don't use the term four cycling, they use the term slightly rich. When you read the description of slightly rich, without fixating on the term four cycling, it's pretty clear that they meant the backed off from peak setting, that sport fliers (the ones who want their engines to last) use.

Most sport fliers I know don't set their engines for absolute peak, this is an area of performance that's usually only needed for people who race, or feel the need for speed, and are willing to pay the price of buying replacement parts or engines. They also don't try to fly at a setting that you would call four cycling. They usually fly at a slightly rich setting.