So. It's back. Again. I tried the immediate fix of punching the steering wheel in anger. That didn't work.
After last fix, car has been fine for well over a week, however has decided it doesn't want to play again yesterday....
Beginning to wonder if it may be the earth underneath battery tray causing issues.
Anyway, differing from last time, the misfire seems to continue no matter how much you mess about with and/or swap around the coils...
Will investigate tonight and post results. Any thoughts in the mean time?