  The extreme low-luminosity supermassive black hole Sgr A* provides a unique
laboratory in which to test radiatively inefficient accretion flow (RIAF)
models. Previous fits to the quiescent Chandra ACIS-S spectrum found a RIAF
model with an equal inflow-outflow balance works well. In this work, we apply
the RIAF model to the Chandra HETG-S spectrum obtained through the Chandra
X-ray Visionary Program, which displays features suggestive of temperature and
velocity structures within the plasma. A comprehensive forward model analysis
accounting for the accretion flow geometry and HETG-S instrumental effects is
required for a full interpretation of the quiescent Chandra HETG-S spectrum. We
present a RIAF model that takes these effects into account. Our fits to the
high-resolution gratings spectrum indicate an inflow balanced by an outflow ($s
\sim 1$) alongside a temperature profile that appears shallower than what would
be expected from a gravitational potential following $1/r$. The data require
that the abundance of Iron relative to solar is $Z_{Fe} < 0.32 Z_\odot$ (90\%
credible interval), much lower than the $2~Z_\odot$ metallicity measured in
nearby late-type giants. While future missions like NewAthena will provide
higher spectral resolution, source separation will continue to be a problem.
Leveraging Chandra's unparalleled spatial resolution, which is not expected to
be surpassed for decades, remains essential for detailed investigations of the
densely populated Galactic Center in X-rays.
