Update:
Adjusted fuel to E40 and wasn't able recreate the misfire, even at 34° temp. However, 4th gear logs still show rail pressure crash at low RPM. I've sent the logs to my tuner and they're here if you're interested:
https://datazap.me/u/tnilson/s58-e40...s?log=0&data=9
Next steps: I've ordered a Motiv Reflex fuel controller kit with lpfp sensor and going to log lpfp data to see if that's the culprit. More soon...