After document class, \setkeys{acs}{super = true} fails to alter reference format

[josephwright]

With minimal example

\begin{filecontents*}{\jobname.bib}
@ARTICLE{Abernethy2003,
  author = {Colin D. Abernethy and Gareth M. Codd and Mark D. Spicer
    and Michelle K. Taylor},
  title = {A highly stable {N}-heterocyclic carbene complex of
    trichloro-oxo-vanadium(\textsc{v}) displaying novel
    {Cl}---{C}(carbene) bonding interactions},
  journal = {J.~Am. Chem. Soc.},
  year = {2003},
  volume = {125},
  pages = {1128--1129},
  number = {5},
  doi = {10.1021/ja0276321},
}
\end{filecontents*}
\documentclass[journal=bichaw]{achemso}
\setkeys{acs}{super = true}
\author{Andrew N. Other}
\email{a.n.other@academic.uu}
\affiliation
  {Department of Chemistry, Unknown University, Unknown Town}
\title{\emph{Some} things I did}
\begin{document}
Some text~\cite{Abernethy2003}.
\bibliography{\jobname}
\end{document}

the setting super = true has no effect. This happens as the way super is currently designed works on a one-shot basis for loading natbib.