[Laird Scooby]

You didn't inadvertently swap the LT connections when you fitted the new coil did you? The Blue/Red wire should be on the +ve terminal - worth double-checking as reversing a coils polarity can cause bad starting, poor running and speed-specific misfires.

Intrigued by the mystery component, have you got a photo? Could be the dim-dip resistors at a guess.

I'm making a guess that the other sensor on the hose between turbo and MAF is a pressure sensor possibly to bring on the overboost warning light (or was that only on diesels?) or tell the ECU it's overboosting. Leaks in this hose could cause an overboost condition without warning lights and often with overboost, detonation/pinking/knocking occurs so the knock sensor could be retarding the ignition to save the engine.

Have you tried altering your driving style to see if you can recreate the misfire at a different engine speed?