Overview of the flattening of the effective potential q_Φ at Galactocentric coordinate x = 15 kpc of different analytical MW mass models, namely those by Bovy (2015), Price-Whelan (2017), McMillan (2017), and Cautun et al. (2020), and MW mass models constrained by stellar streams, namely Koposov et al. (2010), Küpper et al. (2015), Bovy et al. (2016), Malhan & Ibata (2019), Palau & Miralda-Escudé (2023), and Ibata et al. (2024), globular cluster dynamics (Posti & Helmi 2019), and the HS (Dodd et al. 2022). This figure also shows two Galactic potential models by Vasiliev (2024) with the ℒ3, ℳ11 and ℒ2, ℳ11 halo models. Models that are based on constraints of the DM halo shape are shown with circles, models that assume a spherical DM halo are shown with diamonds. Solid symbols indicate models for which uncertainties on the effective potential could be derived, as described in the caption of Fig. 13. Open symbols indicate that no uncertainty on the potential parameters was available, and hence no uncertainty on the effective potential flattening could be derived.