E5d — final knob round (beta x frame smoothing)

Selection scores (seeds 2-3): b0.6_s2=4.532, b0.6_s4=4.556, b0.75_s2=4.640, b0.75_s4=4.671, b0.9_s2=4.831, b0.9_s4=4.874

Held-out (seeds 4-6): ZA 4.98 +/- 0.27; b0.6_s2 4.52 +/- 0.18 (-9% vs ZA; oracle bound 4.47; E5c winner 4.64).