2013 Ford F-150 Misfire Under Load - P0306 and P0300

My 2013 F-150 runs perfectly fine around town and at idle. However, as soon as I try to pass someone on the highway and the boost kicks in, the whole truck starts shaking and the Check Engine light flashes. If I back off the throttle, the light goes out or stays solid. It feels like a massive misfire. I've already replaced all 6 spark plugs with Motorcraft SP-534s gapped to 0.030, but the issue persists on cylinder 6 specifically. Also seeing some oil residue in the intercooler piping when I checked for boost leaks.