The paper explores the possibility of combining pre- and post-recombination new physics to address the Hubble tension, focusing on models with varying electron mass and a sign-switching cosmological constant. The study considers two models: the $ \Lambda CDM + m_{e} + \Omega_{K} $ model, which features a time-varying electron mass and non-zero spatial curvature, and the $ \Lambda_{s}CDM $ model, which involves a sign-switching cosmological constant. These models are tested against CMB, BAO, and SNeIa data to assess their ability to resolve the Hubble tension. The $ \Lambda CDM + m_{e} + \Omega_{K} $ model, which allows for a time-varying electron mass and non-zero spatial curvature, is found to reduce the sound horizon and thus the inferred Hubble constant $ H_0 $, but the results are not sufficient to fully resolve the tension. The $ \Lambda_{s}CDM $ model, which features a sign-switching cosmological constant, also shows some ability to alleviate the Hubble tension but does not fully resolve it. When combined, the $ \Lambda_{s}CDM + m_{e} $ model performs worse than either individual model in terms of the inferred central value of $ H_0 $, despite having larger uncertainties. The study highlights the critical role of the matter density parameter $ \Omega_m $ in resolving the Hubble tension. The $ \Lambda CDM + m_{e} $ model requires a higher $ \Omega_m $ to maintain the acoustic scale, while the $ \Lambda_{s}CDM $ model requires a lower $ \Omega_m $. The combination of these models leads to a negative correlation between $ m_e/m_{e,0} $ and $ \Omega_m $, which complicates the resolution of the Hubble tension. The results show that combining pre- and post-recombination new physics does not significantly alleviate the Hubble tension, and that the matter density parameter $ \Omega_m $ plays a crucial role in this context. The study underscores the importance of assessing the tension-solving directions in the parameter space of new physics models and how these correlate with shifts in other standard parameters. The findings suggest that a combination of early- and late-time new physics may not be sufficient to fully resolve the Hubble tension, and that further research is needed to explore alternative models and parameter combinations.The paper explores the possibility of combining pre- and post-recombination new physics to address the Hubble tension, focusing on models with varying electron mass and a sign-switching cosmological constant. The study considers two models: the $ \Lambda CDM + m_{e} + \Omega_{K} $ model, which features a time-varying electron mass and non-zero spatial curvature, and the $ \Lambda_{s}CDM $ model, which involves a sign-switching cosmological constant. These models are tested against CMB, BAO, and SNeIa data to assess their ability to resolve the Hubble tension. The $ \Lambda CDM + m_{e} + \Omega_{K} $ model, which allows for a time-varying electron mass and non-zero spatial curvature, is found to reduce the sound horizon and thus the inferred Hubble constant $ H_0 $, but the results are not sufficient to fully resolve the tension. The $ \Lambda_{s}CDM $ model, which features a sign-switching cosmological constant, also shows some ability to alleviate the Hubble tension but does not fully resolve it. When combined, the $ \Lambda_{s}CDM + m_{e} $ model performs worse than either individual model in terms of the inferred central value of $ H_0 $, despite having larger uncertainties. The study highlights the critical role of the matter density parameter $ \Omega_m $ in resolving the Hubble tension. The $ \Lambda CDM + m_{e} $ model requires a higher $ \Omega_m $ to maintain the acoustic scale, while the $ \Lambda_{s}CDM $ model requires a lower $ \Omega_m $. The combination of these models leads to a negative correlation between $ m_e/m_{e,0} $ and $ \Omega_m $, which complicates the resolution of the Hubble tension. The results show that combining pre- and post-recombination new physics does not significantly alleviate the Hubble tension, and that the matter density parameter $ \Omega_m $ plays a crucial role in this context. The study underscores the importance of assessing the tension-solving directions in the parameter space of new physics models and how these correlate with shifts in other standard parameters. The findings suggest that a combination of early- and late-time new physics may not be sufficient to fully resolve the Hubble tension, and that further research is needed to explore alternative models and parameter combinations.