Symmetry, continuity, differentiability, accuracy and efficiency are the essential requirements of a compact model. To ensure this need, in this work, we implement two major updates in drift resistance model in BSIM-High Voltage (HV) compact model. The updated model is faster while ensuring infinite continuity and differentiability around V-ds = 0V, leading to correct slope of harmonics. The model is validated with the numerical simulated and experimental data of HV transistors.