the 273 sampled payloads repeatedly found a finite interior shell-diffusion threshold, with the estimate usually about 0.35 to 0.53, widening only occasionally to about 0.60, and bracket_width collapsing from about 1.91e-07 at N=512 to about 2.91e-12 at N=2048. Past that threshold the shell-focused mode stayed strong instead of marginal: shell mass sat near about 0.63 to 0.67, the localization measure climbed from about 0.61 to 0.63 at the smallest shells up to about 3.27 to 3.31 in the largest runs, and the leading growth rate remained clearly positive near about 5.83 to 8.28.