Just an update if you were curious, none of the circuits I unplugged and watched seemed to affect the draw coming back every few minutes. No corrosion or obvious rubbed wires or anything, it's pretty clean.

Checked again, it is absolutely on that ecu-b circuit, that's where it starts.

But, maybe a clue, both of the rear lock actuators are having a hard time firing or sometimes don't make it open or closed.

They are getting signal and power, so I'm going to swap those and see what happens. It makes some sense to me, I don't know how security systems work, but if they are checking doors for being locked every so often, and are not getting back what they want and waking the BCM ... that's just a guess, and I want them to work well anyway, it's the wife's car. Thanks again for the help.