Epitaxial thin films serve as a versatile platform for tailoring the properties of stronglycorrelated materials, such as Mott insulators, through precise strain engineering. By leveraging lattice mismatches between the film and substrate, controlled distortion can be introduced into the film’s crystal lattice, enabling modulation of the material’s electronic, magnetic, and structural properties. Such strain-driven tuning is pivotal for exploring novel phases and functionalities in complex oxides. Meanwhile, externally imposed strain can stabilize the coexistence of multiple phases and promote symmetry-lowering transitions accompanied by twinning and intricate structural heterogeneity, complicating the interpretation of the structure-property relationships in epitaxial systems. Addressing these complexities requires advanced characterization approaches capable of resolving nanoscale structural variations with high precision. In this work, we develop and apply synchrotron-based X-ray characterization techniques to investigate the impact of epitaxial strain on structural phase transitions in Mott Insulators. Specifically, techniques such as large-volume reciprocal space mapping, scanning X-ray nanoprobes, and phase-sensitive diffraction imaging are employed to provide insights into crystallographic symmetries, lattice distortions, and nanoscale structural heterogeneities associated with symmetry- lowering transitions. By elucidating how anisotropic strain modulates structural phase transitions in Mott insulators, this work advances our fundamental understanding of strongly correlated systems and informs the design of next-generation computing and memory devices based on emergent quantum phenomena.