Newb Tuning Question..

[modulation]

I'm starting off simple tuning a N/A OBDI ka24de. I'm simply modifying A/F Ratios and will get dyno time to see what AFR produces mean best torque (I think it'll be ~13.0:1 but I'm also going to do some dyno runs with 12.5:1 and 13.5:1.) Then I will move on to timing until my AFR's are off, then add/remove fuel, then adjust timing, rinse and repeat.

My question is about using the AFR 3D Trace and the "Display Type."
I've written a small python script to strip the csv files and only take the lines of data where TPS > 3.5 volts. This allows me to only look at AFR when I'm full-throttle. But I notice that the Minimum/Average/ Maximum numbers in each cell aren't as close as I'd expect. I know the best solution would be infinite dyno time where I could just dial in the AFRs that give me the most power and not care about the actual number, but I'd like to try and get as much done ahead of time as dyno time is $$.

When one tunes by AFR should they look at the average (excluding decel), maximum or minimum AFR in the cell?

Thanks in advance.