  Spinor-vector dualities have been established in various exact string
realisations like orbifold and free fermionic constructions. This paper aims to
investigate possibility of having spinor-vector dualities on smooth geometries
in the context of the heterotic string. As a concrete working example the
resolution of the T4/Z2 orbifold is considered with an additional circle
supporting a Wilson line, for which it is known that the underlying orbifold
theory exhibits such a duality by switching on/off a generalised discrete
torsion phase between the orbifold twist and the Wilson line. Depending on this
phase complementary parts of the twisted sector orbifold states are projected
out, so that different blowup modes are available to generate the resolutions.
As a consequence, not only the spectra of the dual pairs are different, but
also the gauge groups are not identical making this duality less apparent on
the blowup and thus presumably on smooth geometries in general.
