The parts of code that handled the BlendMode and emissivity were likely left out from TerrainFallbackConsumer because vanilla models cannot use them, but QuadTransforms can still change the quad's material and thus BlendMode and emissivity. The fallback consumer will ignore these properties even though it should not. AbstractMeshConsumer's code correctly handles these properties, so this code should likely be abstracted and used by the TerrainFallbackConsumer as well to fix this issue.