We present a study of the Berezinskii-Kosterlitz-Thouless (BKT) transition in mildly disordered NbN nanoporous (NP) films. The measured superfluid stiffness, Js, is found to be much lower than that predicted considering a reduced geometric area. For a 5 nm thick NP film, a distinct BKT transition is observed. By fitting the experimental data via the BKT renormalization-group equations, we show how both Js and the vortex-core energy, μ, decrease in the presence of nanopores. The variation of Js and μ is also reproduced theoretically via Monte Carlo numerical simulations on a 2D diluted XY model. Our results show that nanopore geometries effectively enhance the 2D nature of the superconducting films, increasing the parameter space to explore the BKT physics while offering a pathway to systematically control the two energy scales, Js and μ, that govern the vortex physics in these systems.