I just look and study a bit from Doom 3 editor and i see the secret to game quality in Doom 3 editor is a ligths shaders and shadows and particles.On BGE never possible used a portable functions o C and C++ about this 4 fundamentals topics for increment performance and quality to BGE? May be only after need port physics work in C and C++
I don’t understand, but in any case if you feel like adding features in the engine, here are the sources:
Feel free to add anything, it’s all C++ (and Python for the Blender UI)
try look editor of doom 3 look like work lights, shadows and shaders and particles and textures and you will understand diference between quality and performance understand?