DeepGEMM uses kind::mxf4.block_scale.block32 (MXFP4, UE8M0 scales, 32-elem blocks). DSV4 uses NVF4: kind::mxf4nvf4 (E2M1 microscales, 16-elem blocks). Using MXFP4 would require E2M1->UE8M0 conversion. NO CONVERSIONS. Rewriting fused router in CuTeDSL with MmaMXF4NVF4Op (sf_vec_size=16).