  Graphene subjected to chiral-symmetric disorder is believed to host zero
energy modes (ZEMs) resilient to localization, as suggested by the
renormalization group analysis of the underlying nonlinear sigma model. We
report accurate quantum transport calculations in honeycomb lattices with in
excess of $10^{9}$ sites and fine meV resolutions. The Kubo dc conductivity of
ZEMs induced by vacancy defects (chiral BDI class) is found to match
$4e^{2}/\pi h$ within 1% accuracy, over a parametrically wide window of energy
level broadenings and vacancy concentrations. Our results disclose an
unprecedentedly robust metallic regime in graphene, providing strong evidence
that the early field-theoretical picture for the BDI class is valid well beyond
its controlled weak-coupling regime.
