yes maybe most of MMDers won't use hard (and real) lighting/raytracing environments and they'll just go on using their favorite shaders. reading those tutorials I started being persuaded that the recently increasing popularity of Lighting environments like Ra圜ast MMD, IK polish and others, makes the need to provide models with some extra sliders other that the usual ones. Many models have their own sliders/facial to control some materials settings, for example in order to change some colors, to increase or decrease the reflections on some parts, and so on.
Some months ago when I was still working on my previous C6V2 base, I've read some articles and tutorials, mostly written by Trackdancer, DisastrousBunny and vasilnatalie or found on, all about the various settings involving the model's materials, and accessible from the Materials Tab in PMXEditor. Usable for both raytracers and for common uses with other classic shaders