thanks for the big and necessary update but keep in mind that yteh function must keep a very similar behavior by default than teh previous version.

That is the color and source/target should be the same as previous version . It is OK to have parameter that change this default behavior and you can use the values you want in your examples but this update should not change too much the other examples that use the function (except for the fill of the densities it is much better than the previous plot).