Yes, it is very interesting!
The thing is that even within the same RPM range, pick one, 1300RPM for instance, look at how many cells are in that column. Every single one of those represents a different load on the engine. Most likely, there is an opportunity for power by optimizing each cell (and surrounding of course), which leads to the blending comments. But going back to the individual cells, based on MAP at a given RPM. Just randomly picking a situation, say you are starting off on flat ground, unloaded. Then imagine you are doing that with the rig going slightly up hill. Then the same but steeper. Now pulling a trailer. And so on and so on. Every one of those will likely be crossing 1300RPM in a different timing cell, since the load (MAP) has changed. I recall seeing somewhere that timing is again easier to get right with LS tuning. I've got manual trans, I suppose an auto could be simpler to tune for as well. Don't forget though, that timing and fueling are interrelated.
Took me quite awhile to get fueling and timing decent under heavy load, as test driving under the same conditions to see if my tune was better or worse was difficult. But what a change pulling a hill with the trailer when fueling and timing was closer to being optimal. Literal difference of 50MPH vs 60MPH on the same grade.
Even on a carbed setup its entirely possible to run high initial timing to get good idle, still have a good curve for power, AND have it cruise with decent timing for economy...but it's a lot tougher than it is with a computer, because with an ECM/PCM you can make the timing whatever you want, at the point you want it. Obviously you do what the engine wants, not what you want, but being able to dial timing in, basically unencumbered by mechanical difficulties and limitations, changes the way you look at timing strategy.
