All I can is ahhhhh......new alt did the trick.

What compounded the diag was the fact that in between testing/isolating, I was putting the X on a charger...

X would be okay on local small trips as I pretty much charged her back up,.
Not so much when I took a long one......

Bottom line.
Never a error on the cluster
I suspect it was getting proper V , alternator just not putting out enough A. Long drive, vehicle drawing off the battery, etc, etc.

I thank the big guy up there, as both times it straight up shutdown on me when I was driving, I was on a local street.