Bill, I clearly misunderstood the intent of introducing that "averaging function" (had a struggle understanding the function itself for a bit), but now it's clear to me that its purpose was to illustrate a key point: negatives and numbers greater than one exist in Poser. That fact is going to be of utmost importance to understand when making materials out of nodes using colour or for that matter doing anything with nodes at all.

I opened this discussion with the strong suspicion that my so-called "observations" were giving me false conclusions. Basing conclusions on what is observed and inferring that "because I can't see a change, therefore no change must be happening" when working in such a math-saturated environment was going to be fraught with error: I sorta figured that. What I needed to have were tools to disprove my first conclusions, which you have provided with your "averaging" function.

In your subsequent posts, I notice your experimentation method produces quicker results than plugging into a PoserSurface Alternate_diffuse channel for purposes of rendering. So, those methods were bogus as well, since a rendered surface is going to be affected by the existing lights, which would affect outcomes too much for there to be a consistent, reproducible result: too many variables.

I'm talking basics, here. Those that say "you need to do experiments" fail to understand that Dummies like me haven't a clue what should and shouldn't be in a lab setting. The reason I plugged into the Alternate_Diffuse channel was because I was of the understanding that it only passed on to PoserSurface what was plugged in, which made it a known entity.

And here in the material room, there were so many unknowns.

So, what do I now understand? Regurgitating:
--Negative numbers exist and must be reckoned with, as well as values greater than one.
--With colour, you deal with a tupple, so any maths you apply is applied to each member of that tupple.
--Minute colour changes can and will have massive impact on surfaces.
--Most importantly, don't rely at all on what you see: trust the maths, get the head around the maths, start with maths... the nodes will grow out of that

How do I use it in a sentence? Know what you want to do and do it mathematically first.

Your wood grain illustration is mouth-watering, Bill. Second-year, stuff, but definitely mouth-watering. So, I look at those nodes and suddenly realize I'm looking at the result of something that was worked out as a math equation before-hand. The maths actually comes first: the nodes create themselves (virtually) based on the math.

Am I getting any closer?

Monterey/Mint21.x/Win10 - Blender3.x - PP11.3(cm) - Musescore3.6.2

Wir sind gewohnt, daß die Menschen verhöhnen was sie nicht verstehen
[it is clear that humans have contempt for that which they do not understand] 

Metaphor of Chooks