The synthesis of the superheavy element with atomic number Z = 119 via the ${}^{48}$Ca + ${}^{254}$Es reaction represents one of the most promising near-term experimental goals, although theoretical predictions of its evaporation residue cross section (ERCS) are consistently low. Within the di-nuclear system (DNS) model, the driving potential $U(\eta )$ provides the microscopic landscape governing nucleon transfer and compound nucleus formation. We therefore examine how different microscopic inputs modify the fusion path and ERCS predictions for ${}^{48}$Ca-induced reactions on ${}^{248}$Cm, ${}^{249}$Cf, and ${}^{254}$Es. Calculations based on Finite-Range Droplet Model (FRDM) and Weizsäcker-Skyrme (WS) microscopic–macroscopic models are compared, with the former two benchmark reactions evaluated against available experimental data. Within the WS model, explicitly introducing deformation parameters $({\beta }_1,{\beta }_2)$ as independent degrees of freedom reduces the Coulomb potential at the entrance channel, thereby lowering the inner fusion barrier by approximately 1 MeV. The inclusion of shell correction damping at finite excitation energy further modifies the driving potential and fusion probability $P_{\rm CN}$ within the optimized deformation scheme. For the 3n evaporation channel of ${}^{48}$Ca+${}^{254}$Es, predicted ERCS lies in the range of $[0.016,0.167]$ pb around the favorable excitation energy region of $E^{*}=32$–34 MeV. The comparison with previous theoretical studies indicates that the energy region is relatively robust, whereas the absolute cross section exhibits substantial model dependence. These results provide a quantitative assessment of microscopic uncertainties in driving potential calculations for future $Z=119$ synthesis studies.