The QDL–SO10–1 grand-unification sequence defines a closure-first SO (10) -compatible benchmark within the Quantized Dimensional Ledger (QDL) program. Papers #1–#3 established the initial benchmark trilogy: a fixed SO (10) -compatible benchmark, its low-energy phenomenology, and a stress-test / robustness audit. Paper #5 began the executable hardening sequence by revising the gauge-closure target to inverse alphaU = 44. 501718, corresponding to alphaU = 0. 022471, and by rescaling the benchmark proton-decay exposure. Paper #6 supplied a reduced block-level scalar-threshold derivation of the calibrated high-scale offsets, advancing the benchmark from calibrated executable gauge closure to block-level scalar-derived gauge closure. This paper supplies the v0. 4 proton-decay hardening layer. Its purpose is to replace the previous scaling-level proton-decay exposure estimate with a benchmark-level operator calculation. The calculation constructs a dimension-six baryon-number-violating operator basis, assigns Wilson coefficients at the unification scale, evolves them to the hadronic scale using a declared renormalization factor, applies benchmark hadronic matrix inputs, and computes channel-level partial widths and lifetimes. The channel flavor factors used here are benchmark exposure factors, not fitted CKM, PMNS, or Yukawa predictions. The hadronic formula is a declared benchmark normalization for reproducible exposure accounting, not a full lattice-QCD plus chiral-effective-field-theory treatment. Using MXY = 1. 00 x 10¹6 GeV, gU squared = 0. 282379, and gU = 0. 531393, the base gauge-mediated Wilson scale is C₀ (MU) = 2. 823789 x 10^-33 GeV^-2. With benchmark running factor AR = 2. 5, pion matrix element Wₚi = 0. 012 GeV³, kaon matrix element WK = 0. 010 GeV³, and declared channel flavor-exposure factors, the benchmark central lifetimes are: tau (p to e+ pi0) = 2. 162772 x 10³6 yr, tau (p to mu+ pi0) = 8. 651086 x 10³6 yr, tau (p to anti-nu K+) = 1. 453338 x 10³8 yr, tau (p to anti-nu pi+) = 8. 676449 x 10³6 yr, and tau (p to e+ K0) = 3. 310443 x 10³8 yr. The benchmark survives v0. 4 operator-level proton-decay exposure: all benchmark central channel lifetimes are above present experimental limits, with the cleanest gauge-mediated benchmark channel remaining p to e+ pi0. This result does not complete the QDL–SO10–1 flavor program. The next paper, Paper #8 / v0. 5, replaces benchmark exposure factors with flavor and leptogenesis feedback. The v0. 4 standard is not proton-decay avoidance; it is operator-level exposure with explicit survival and failure channels.
James D. Bourassa (Mon,) studied this question.