K. Now also the 3 and 4-way blend shaders are done. The result is kinda nice, and even though I realize I might haven't selected the finest textures available to perform the tests and create this example scene, I'm still happy with the result nonetheless.
There are now shaders for a few scenarios that might appear whilst level designing (the toolset will be even more complete once I finish working on the angle based shader). Each of the 2, 3 and 4-way vert color blend shaders have 3 levels of quality which linearly affect performance, meaning that an ugly simple lerp between the materials will be more efficient than the height based check (simple cutout)... and the height based check with smooth transition phase will be more performance heavy. But all three variants are 100% PBR.
A better custom material inspector will follow soon, as well as a custom mesh vert color painting utility. What's also on my personal wishlist is a vertex position editor like the displacement tool in Valve's Hammer Editor, which always brings back many good old memories, but that will have to wait for now. Because for now, this glass of delicious Caol Ila 12y single malt whisky is more than just well earned and will suffice for today.
Stay tuned for more!