So I found an old PDF with Pipcecil's DTC freeze frame info from when he had the OBC failure back almost a year ago [thread here][PDF here]
A few things I've noted from this:
OBC amperage is shown only as a single digit (8A), not a lot of precision there.
Available HV Battery power is 110kW, which matches EV CAN message 1DC byte 0.
"Chargeable Pwr MAX" for L2 charging is somewhere around 32kW
Regen Power is a separate value than chargeable power, and is a hilarious error of 256kW during charging (so probably a byte and an extra nibble bit on a message).
Coolant temp was 60F and charger temp was 70F so the temp sensor for the charger is probably not on the heatsink (probably on the control board) since the charger had just started up.
The quick charger voltage sensor is pretty accurate (maybe) with 3 digits after the decimal (5 sig figs!).
"VCM State" is listed as 130, which is what message 1F2 byte 5 is on my leaf when L2 charging.
I previously suspected that 1F2 was from the VCM, and after going through some logs and consulting the "EVC" section of the service manual, I've confirmed that byte 5 on 1F2 is the VCM state and thus the message is coming from the VCM.
A few small puzzle pieces have found their place.