Smart insole systems with pressure sensors have revolutionized real-time gait analysis. Existing insole systems lack investigation into validating and analyzing optimal sensor placements for accurate estimation of temporal gait parameters (TGPs). A novel smart insole system optimized for precise TGP measurement was developed to fill this research gap. We compared data from three healthy participants with varying foot sizes (5.5, 9.5, and 11.5 US men’s sizes) collected by the proposed insole system and a reference instrumented treadmill for validation. Bland-Altman plots and correlation analysis were used to assess the agreement between the reference system and the proposed insole. Our findings show that averaging over 100 continuous strides yielded TGPs with a 25 ms precision or less. Accuracy estimations for different foot sizes ranged from 8 to 40 ms. These results confirm the effectiveness of the optimized, customizable insole design for accurate TGP estimation.