Great stuff. I was about to try doing something similar myself to see how close to the limit of the AMM I am. My logger only reads at 10Hz though, so I won't get such detailed information. I may try finding a better logger. What would you say would be the minimum sample rate I could get away with?
It would be very interesting for you to remove the AMM screens and then try the same test again to see if there is a difference in the shape of the curve (once the ECU has learnt the new setup).