Asking for a friend.
I suspect there is no way currently to disable material nodes in legacy BGE/UPBGE. Am I wrong. Thanks.
- Switch material at run-time with duplicate material that has material nodes deactivated (performance costly obviously)
- Replicate the raw GLSL for the material shader and alternately toggle it on/off at run-time with KX_BlenderMaterial.shader OR KX_BlenderMaterial.getShader().setSource()