OK, so some more diagnostic data.
After I tested it yesterday, I put my 1A Noco trickle charger on it, expecting it to take a while. I went out to check on it before bed a couple hours later and the light already went green - so Noco didn't think it was very discharged - by definition 2Ah at most? Seems odd.
I let it sit overnight and tested it again this morning - still a bit of overvoltage on it - 12.65V. I decided to go ahead with a draw test anyway even though there was no signs. Within 30 minutes it was at about 15mA and holding. So its drawing nothing when off.
Didn't drive it today. Just now I tested again. 12.55V, more CCA than rated, 95% charged, resistance at 3 milliohm's. So the battery looks good now.
I guess I will run it some more and check again. Maybe the factory charge setup just can't get it all the way there, coupled with a cheap Clarios battery and an imprecise battery tester, combined with my OCD and the perception of a problem?