We compare the data quality before and after the refined data processing. Both data products were generated using master background subtraction. The refined processing introduces three major improvements. (1) The anomalous rise of the continuum beyond 2.7 μm is removed. This feature was caused by an “MSA FAILED OPEN” event, which predominantly affected the emission region associated with LACES104037-LyC. (2) Spurious emission-line features are eliminated. Because the JWST pipeline algorithm for removing “snowball” artifacts cannot fully mitigate contamination from faint residual features, we visually inspected the spectra and identified the contaminants that most strongly affect the emission lines of LACES104037-LyC. The most impacted regions are those near [N II] λ6583 and Hβ. (3) Contamination at the edges of the data cube is effectively removed. The left panel shows the result obtained after stacking the optical continuum. Compared to the pre-processed data, most of the edge-related contamination is successfully mitigated. We note that, in the optical continuum image presented in the main text, the contaminant in the upper-left corner is masked and noise-filled.