  We study a class of orientifold compactifications of type IIB supergravity
with fluxes down to 4D in connection with truncations of half-maximal gauged
supergravities yielding isotropic STU-models with minimal supersymmetry. In
this context, we make use of a group-theoretical approach in order to derive
flux-induced superpotentials for different IIB backgrounds. We first review the
toroidal case yielding GKP-like superpotentials characterised by their
\emph{no-scale} behaviour. We then turn to $S^{3} \times S^{3}$ and $S^{3}
\times \mathbb{T}^{3}$, which, surprisingly, give rise to effective
descriptions of non-geometric $Q$- and $P$-fluxes through globally geometric
non-toroidal compactifications. As a consequence, such constructions break the
no-scale symmetry without invoking any non-perturbative effects.
