During the current allocation period, we developed and validated machine-learned interatomic potentials for rocksalt-derived NbN and used them to investigate its structural stability across 225 NbxNy compositions. The results show that ideal stoichiometric cubic NbN is dynamically unstable at 0 K and relaxes toward a slightly tetragonal structure, while Nb and N vacancies progressively suppress this distortion and promote cubic-like lattice metrics. Finite-temperature molecular dynamics further indicates that thermal fluctuations reduce the time-averaged distortion. In the next allocation period, we will extend this work through systematic phonon and vibrational free-energy calculations for vacancy-containing structures, broader sampling of defect configurations, long-timescale molecular dynamics, and studies of diffusion and competing NbN phases. Continued access to Tetralith is therefore required to complete the finite-temperature thermodynamic and dynamical description of defective NbN and support the resulting publications.