  Supersymmetric compactification with moderately large radius (${\rm Re}< T >
\sim {\cal O}(10)$ or more) not only accommodates supersymmetric unification,
but also provides candidates for an inflaton in the form of geometric moduli;
the value of ${\rm Re}< T > > 1$ may be used as a parameter that brings
corrections to the inflaton potential under control. Motivated by a bottom-up
idea "right-handed sneutrino inflation" scenario, we study whether complex
structure moduli can play some role during the slow-roll inflation and/or
reheating process in this moderately large radius regime. Even when we allow a
tuning introduced by Kallosh and Linde, the barrier of volume stabilization
potential from gaugino condensation racetrack superpotential can hardly be as
high as $(10^{16} \; {\rm GeV})^4$ for generic choice of parameters in this
regime. It is also found that even very small deformation of complex structure
during inflation/reheating distorts the volume stabilization potential, so that
the volume stabilization imposes tight constraints on large-field inflation
scenario involving evolution of complex structure moduli. A few ideas of
satisfying those constraints in string theory are also discussed.
