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Light is a powerful tool, capable of inducing phase transitions in quantum materials on-demand. Light-induced states can, however, exhibit complex phase separation at the nanoscale. Here, we investigate transient nanotextured heterogeneity in vanadium dioxide (VO₂) thin films during a light-induced insulator-to-metal transition (IMT). Room temperature, steady-state, phonon enhanced nano-optical contrast reveals preexisting “hidden” disorder.  The observed contrast is associated with inequivalent twin domain structures. Upon thermal or optical initiation of the IMT coexisting metallic and insulating regions are observed. Correlations between the transient and steady-state nano-optical textures reveal that heterogeneous nucleation is partially anchored to twin domain interfaces and grain boundaries. Ultrafast nanoscopic dynamics enable quantification of the growth rate and bound the nucleation rate. Finally, we deterministically anchor photo-induced nucleation to predefined nanoscopic regions by locally enhancing the electric field of pump radiation using nano-antennas and monitor the on-demand emergent metallicity in space and time.