I have new idea that would be great in Cura
By painting the area you define where on the object the change in fill goes rather than use blocks. In the bottom one the idea is to use patterns such as a stochastic pattern. Everywhere the pattern is, it goes through the object as a solid and as it vignettes away from the near solid on the blade edge the dots become smaller blending into the regular infill that way you can alter the strength, lightness and also the momentum.