The 6 February 2023 Kahramanmaraş Earthquakes (Mw 7.8 and Mw 7.6) caused extensive deformation along the East Anatolian Fault Zone, producing significant north-south displacements. Standard InSAR methods face significant challenges in resolving near-field deformation due to phase decorrelation caused by high displacement gradients and heavy snowfall. This study demonstrates the capability of Subswath and Burst Overlap Interferometry (SBOI) which leverages all possible overlap regions of Sentinel-1 TOPS-mode to retrieve along-track deformation, providing improved resolution of 3D displacement fields. We develop a novel methodology to calculate pixel-based scaling factors for spectral separation, enabling accurate deformation measurements in both burst and subswath overlap regions. The SBOI dataset is combined with azimuth and range offset tracking outputs to generate 3D displacement fields and perform coseismic slip inversion using an unsmoothed Bayesian approach. Results reveal significant improvements in constraining north-south deformation, reducing residuals, and decreasing uncertainties in the slip inversion model compared to solutions without SBOI. Linear regression analysis between solutions with and without SBOI demonstrate $\sim$40$\%$ reduction in RMS error for the north-south component of 3D displacement field. Near-field SBOI profiles also capture detailed deformation gradients along fault ruptures, offering insights into fault kinematics and rupture dynamics. This study highlights SBOI as a powerful tool for resolving high-gradient deformations and enhancing 3D displacement fields and geodetic slip models, particularly in regions experiencing large coseismic deformation with significant north-south components, where conventional InSAR and SAR measurements are insufficient.