I noted a few things while driving around today, after my last post above.
Before getting in and starting the engine, I was measuring the draw down from full charge to a place I see it nominally settling after each recharge cycle, checking voltage with a meter each hour or so. My goal was to observe how quickly the voltage bled off due to the normal parasitic draw.
I had the meter on the battery getting ready to make my final measurement before heading out and starting the whole cycle again, when my wife opened the door to get the dogs into the back seat. Wow, the voltage dropped a lot, like a half volt. At that instant I realized all my previous measurements of battery voltage and conclusions regarding its state were wrong, as I was measuring the battery while still connected to the truck. The truck's systems draw from the battery at various rates as systems slowly shutdown or power up (like when you open a door). Lacking any clear documentation of what happens when and how much those things represent in power draw, measuring battery voltage without the battery being disconnected from the truck is a fool's errand, I think.
I am intrigued enough about where my battery (and charging system) is at, I think I will take the time to disconnect and reconnect the battery when taking measurements. This will require me to do a fair amount of TPMS relearning, but I have a big compressor, so it shouldn't actually be a big burden.
Another thing I finally got to see today while driving around was the RVC reacting exactly like
@iamdub said it would. When the voltage dropped well below 14v (on the dash, sometimes looking more like 10v), it didn't appear correlated to the RPM of the engine or even when I turned systems like the AC, radio, rear window defroster on and off, it just seemed at times to decide apparently randomly, when to charge the battery and when to discharge it.
Not sure anything fundamental has yet been resolved in my understanding, but seeing how much draw is triggered by just opening a passenger door, lead me to really want to know if my BCM has that sw upgrade called out for 2007 model year's with charging issues.
Some fun.