There is one behavior in your log that I am fixated upon: I can see a large oscillation in the fuel trim at the same time that there is a step change in commanded evap purge. I have a hypothesis: if evap purge delivers uneven flow or too much fuel vapor, it will be difficult for the car to control fueling leading to a surge in engine speed.
In the datalog I can see some things that are reasonable along this hypothesis: when the evap purge is active, the car will sometimes suddenly use the short term fuel trim to remove fuel and it will close off the evap purge. Both of these behaviors are consistent with your previous post stating an expectation of overly rich operation. I also think that this is consistent with too much/uncontrolled (uneven) fuel vapor delivery via the evap purge system.
When the fuel is removed (both at the injectors via STFT and at the evap tube via command on the valve), the engine speed begins to fall. The car then advances timing in order to catch the idle, leading to a somewhat lean condition with advanced timing-> this causes a surge in engine speed. Is this a reasonable explanation?
The fuel trim then oscillates as the system returns to stabilization, and the car begins opening the evap valve in a process that allows the event to occur again.
On my car, I can also see the short term fuel trim remove fuel at the injectors when the evap purge is initially opened. However, in my case the amount of fuel removed (extent of the trimming action) is not very severe and the car does not need to close the evap valve via command. I also see the STFT stabilize over most steady state conditions. Similarly, the engine speed does not experience a surge, but rather remains closely coupled to throttle position and timing advance (note: my throttle position range is 12-82%, since the OBD parameter returns a value that is not zero-corrected).
Finally, when I go to full open throttle, the car moves to open loop fueling (the STFT and evap purge command go to zero). Thus, it would be unlikely for a fuel delivery problem at the evap canister to manifest during full throttle or during warmup since the evap system and oxygen sensor-based fuel trimming action should be inactive. This is also consistent with your previous post indicating that this event is observed at part throttle and after warmup, and I believe that it is consistent with my hypothesis as well.
I guess that if I wanted to try to troubleshoot this system, I would see if there are partly clogged lines in the evap purge system, or if the carbon canister has a bypass leading to direct fuel vapor coming from the gas tank to the intake. well, I don't actually know how the flow lines are routed through that system.. so much of this is a guess.
Does any of this seem reasonable?