That's a wee bit cheeky since, strangely enough, I have read about it! Additionally I have many years of setting up Wifi in different scenarios where the "ideal" hasn't worked as well as using an alternative setup (in channel choices). Unfortunately we can't control the environment very much and we certainly can't control the channels others are using or their hardware or whether their channels are fixed or auto or whatever else. I accept your recommendation as a starting point. I'm just saying that there will be situations when some variation may work more successfully in practice.