hmm yea I see what you mean. the crossover points are not shown anywhere and then if you add/remove slots to a dimension they change to some other set of unseen crossover points, which would break existing expression maps, though I guess in ViPro it breaks them too right? If you add more Y rows to the matrix, then the crossover points all change, just like Synchron, But least you can visibly see what they are and you have the option to slide them around so that existing expressionmaps aren't broken.
The ViPro approach is more explicit.
I'd actually rather have a mode, perhaps for both players, where when you add a row to ViPro (or a slot to a dimension in Synchron Player), the first row will always be cc value=0, the second row always cc value=1, etc.. instead of evenly dividing the range, just keep adding a new row to the end as the next available CC value.
As you put it, that would be much more explicit and consistent when working with expression maps and articulation sets, but not only that, existing tracks you may have recorded with key switches in place even without expression maps and articulation sets.
I can see how the existing method of evenly dividing the range makes sense in certain situations where you are meaning to crossfade through a range of things. However, when using it as a patch selector, then having it be more explicit, with exactly one matching cc value per row...starting at 0...would make a lot more sense.