The blending weights are based off the current cam angles physical position. If the percentages are taken literally, this may not represent the spot in, and weight of, the tables being used to derive the various commanded values.
You have figured out the x,y coordinate system and its all starting to make sense, great.
The snap to points and lines are there to simplify and not have to use the exact reported %weight of each mapped point, which may spread out a lot. This would make computations behind determining various commanded values intense at times. Instead the points and lines allows less points to influence any given condition and should simplify the calibration to just calibrating a set of points or lines (interpolation between two points) for the indicated VCT source. In 15+ mustangs OP mode switched from a single OP mapped point to using the reported % weight of each mapped point, making WOT not as easy to calibrate, but quick transitioning in and out of OP more tolerant and robust. So you don't have to rely on transient table calibration as much.
I think a lot of people take the % and try to spot calibrate with it,which does not work out well. You have to calibrate around the snap to points and lines assigned to the different VCT sources via the arrays.
Wether the weights are determined by an inverse distance, Gaussian, Epanechnikow, or some other kernel, I don't know. I don't think it matters.
The physical cam control is based on a phaser duty cycle feedforward tables and PID position error feedback loop control.
The array tables define which mapped point cam angles belong to each VCT source.
The distance tables define how far along that array it needs to be per load and RPM. This determines the target cam angles, but actual cam position comes down to position error into the PID, phase rate, oil temperature and phaser duty cycle.
The stock phaser control is good, but not enough to hold to perfect points or lines, nor move positions through the arrays as fast as RPM and load change distance and VCT source.
Phasers depend on good oil condition and do wear, get contaminated, age, lose performance and fail over time. So keep an eye on their controlled position error. They may not be even close to where the calibration wants them to be.
Kernalfunction.jpg
For me, above 3500RPM at WOT, running regular spark followed the calibrated borderline values and knock advance wasn't succesfully adding. Running premium knock advance added and it pretty much followed the MBT calibrated values. With in +/-1* on both fuels. Its all below 3500 and high loads that octane made a big difference in where the spark ended up.
With ethanol percentages increasing the combustion reaction kinetics change. This in turn increases torque, and when you increase torque at high RPMs such as 7250, HP goes up by ~1.4x.