In this work, we report an improvement of our previously published 14 global coupled PESs of 3 A′ states of O3. The improvement includes three aspects: (1) We used an improved functional form for the parametrically managed activation function; (2) We obtained smoother PESs by introducing a higher weight for low-lying states; (3) We improved the asymptotic behavior of the coupled PESs by using a better low-dimensional potential in the parametric management step. These improvements are important for improving simulations of O + O2 collisions, and they are of broader interest as well because they are generally applicable to PES fitting of other systems.