Dead line: $R\le 9$

The mass-opt identities give $Q>R/(R+1)$ on a used support of aspect $R$. At $R=9$

No compact $\gamma_9$ can beat the q10 printed leading $1.1013$ while the large-aspect bound stays $9/10$. q7--q10 already recorded this wall against $1.1026$, $1.1021$, $1.1020$, $1.1017$, and $1.1013$.

$R=8$ binds at $1.125$. $R=9.5$ binds at $1.10526>1.1013$. $R=9.8$ with the cut binding would print $10.8/9.8\approx 1.10204$, which still prints as $1.1021>1.1013$. $R=9.9$ binding would print $1.10101$, but only if a compact $\gamma$ at that split both clears $9.9/10.9$ and a printed leading below $1.1013$.

A sharper large-aspect cut would reopen $R\le 9$. Chebyshev $D\cdot M_{-1}\ge 1$ does not.