Maybe the table value is added to another parameter to determine whether to activate vvt?
So the mid-range values might turn it on depending on another condition, and the 100% cells garantee it's on in those areas?
It sounds like you are getting to the point where you need to have every thing set up on a bench. With some means to simulate engine speed (either some sort of frequency generator that replicates the behavior of the crank angle sensors output and signal shape) or a 60-2 tone wheel attached to a variable speed drive and Bosch sensor.
Then it's an emulator in the original ECU, replace the analogue inputs (AFM, inlet air temp. and coolant temp.) with easy to adjust potentiometers. Replace any PWM or switched outputs with current limited LEDs. Then you can put a duty cycle equipped multimeter on the outputs and see what effect changing that part of the code has while simulating 'X revs' and 'Y load'.
This would help you to make absolutely sure that you are looking at things like the injector map(s), and the (probably need an oscilloscope for this one) ignition map(s).
Another thing which will be in the code is the ECU's calibration table for the analogue inputs. Nissan had dedicated calibration codes for their AFM tables and they were different for different AFM's.
The trouble is, if you start adjusting it, it would effect the out behavior of the injectors in the same way a lot of interceptor tuning devices change the main load sensor's signal.
So it may be easy to misinterpret the AFM calibration table as the main injector map. You modify this map and the injector duty cycle changes (much easier to see that than see innition timing changes when stuff is simulated on a bench).
The big problem, if that happens, is that while you may be able to achieve the desired air fuel ratios when tuning, the ignition timing would be going all over the place as a result. That is, the ignition map would be accessing area's that the tuner isn't intending it to access. So while you think you are pulling fuel out to correct an overly rich mixture at 1 rev/load point, you would also be causing the ECU to access a lower load ignition timing point which is typically more advanced. That extra ignition advance MAY cause engine knock or push the engine past its best ignition angle and loose a bit of torque as a result. The tuner may interpret that as a fuel deficiency.
"We leaned it out from a (typically) rich condition and it lost torque. So the engine needs to run rich." (based on readings from an AFR meter and the dyno).
But because they (the tuner) are effecting 2 things at once (injector open times and ignition timing) they could, and probably are, barking up the wrong tree about the requirements of the engine.