Answering some of the above:
The speedo just stopped at 189, It wasn't an under-read so much as its limit, or so it seems. (software?)
I assumed that because of the wheel speed sensors, which provide the rotational speed information to the ECU, the gearing should make no difference to the speed reading. I seem to remember it showed 189 when I did the demo run at last months record meeting, with the bike still in restricted stock form. I didn't pay it any attention at the time and the electronic speed trap at the meeting gave it as 184 point something.
Fommen, I only have the flash and the Akrapovic can, no PCV yet. That's going on next week.