While waiting for my O2 sensors, I ran the durametric this morning.
1: confirmed SAI pump turned on again right away.
2: O2 sensors ahead and behind cat seems to be running in spec
3: picked up some codes. P1117 and P1040 before I started the car. I was able to clear them both this time. And they have not come back.
I'll swap all four O2 sensors and see what happens. For the effort to tackle the SAI system, I'll probably take a look at it too.
More reading and I found a few spots where the post cat O2 sensor failure has lead to bogging and hesitation / loss of power at high revs. This is one of my performance symptoms and happens only occasionally for shot bought (a few seconds).
Anyways. Fun and games.