Round 34 blitz: gemm_hc_down TN=96 tail (-5.0..-7.2%), grd_acc ROLL=true at KS=4 (-1.9..-4.6% on _r2), W8<T_IQ3_S>::block + half4 HS store + IQ2_XS sboff -> 432.78 tok/s 2K prefill, 42.27 tok/s decode, 25.04 tok/s @10.2K