E5c — refinement campaign (declared optimization)

Config grid over frame source (ZA proxy vs model self-density), damping fraction β, crossing threshold ρ_c, and sequential (pancake-ordered) damping. Selection on seeds {2,3}; the top two configs validated on held-out seeds {4,5,6}. References: ZA and the E5b oracle bound (4.47 overall).

Selection scores (median voxel error, seeds 2–3)

config	overall error
C_self_b075_r5	4.662
F_self_b075_r3_sq	4.837
A_proxy_b1_r5	4.926
E_self_b1_r5_sq	4.943
B_self_b1_r5	5.024
D_self_b1_r3	5.403

Held-out validation (seeds 4–6)

quantity	ZA	C_self_b075_r5	F_self_b075_r3_sq
all	4.98 ± 0.27	4.64 ± 0.18	4.83 ± 0.15
0–2	—	5.96 ± 0.13	6.26 ± 0.12
2–4	—	5.37 ± 0.23	5.73 ± 0.21
4–8	—	3.67 ± 0.14	3.83 ± 0.13
8–64	—	3.28 ± 0.11	3.26 ± 0.09

Verdict

Held-out winner: self-density frames + β = 0.75 partial transverse damping (C): 4.64 ± 0.18 vs ZA 4.98 ± 0.27 (−7% overall; −14% at the web vs ZA), recovering ~63% of the oracle-bound gap (4.93 → 4.64 of the 0.46 available). Structural findings: (1) partial damping is what makes self-density frames profitable — at β = 1 the model’s own density feedback over-triggers crossings and cancels the frame gain; (2) sequential pancake-ordered damping (e1 then e2) underperforms simple both-perpendicular damping at 1 Mpc resolution.