  We have used the local-$\delta{f}$ gyrokinetic code GS2 to perform studies of
the effect of flux-surface shaping on two highly-shaped, low- and high-$\beta$
JT-60SA-relevant equilibria, including a successful benchmark with the GKV
code. We find a novel destabilization of electrostatic fluctuations with
increased elongation for plasma with a strongly peaked pressure profile. We
explain the results as a competition between the local magnetic shear and
finite-Larmor-radius (FLR) stabilization. Electromagnetic studies indicate that
kinetic ballooning modes are stabilized by increased shaping due to an
increased sensitivity to FLR effects, relative to the ion-temperature-gradient
instability. Nevertheless, at high enough $\beta$, increased elongation
degrades the local magnetic shear stabilization that enables access to the
region of ballooning second-stability.
