  We discuss the initial conditions problem for inflation driven by the vacuum
energy of a plateau potential, and in particular the Starobinsky inflation. We
show that the supergravity embedding of the $R+R^2$ theory naturally decreases
the size of the acausal homogeneity, required for the low-scale inflation to
occur, thanks to the presence of the dynamical pure supergravitational
"auxiliary" fields. We examine the evolution of the $R+R^2$ fields within a
FLRW Universe. We also find a dependence of the initial conditions problem on
the background spatial curvature.
