Yeah, as posted above:

Clockwise richens L8
Clockwise leans L6

I got the car on the analyser again at the tuner and although it briefly dipped below 3% CO briefly, I think the pot was maxed out, and I couldn't get it to stay under 3% CO, so had no choice to proceed at 3.3% ish

Did a few runs progressively increasing the boost

Final result is 355.8hp @ 24 psi (spiked to about 26psi)

AFR was still well within parameters, but decided 24psi is plenty

Thanks to MSD, and people who have posted on Passionford, you guys are great!

Ben