The challenge associated with the quality of segregated legacy waste, generated through ongoing landfill mining operations involving rapid trommeling of mixed municipal solid waste in India, stems from the inefficiencies in the removal of fine fractions (−6 mm) and the elevated concentrations of contaminants that exceed established regulatory thresholds for off-site reuse applications. This study investigates a full-scale, field-implemented repeated trommeling (FRT) technique aimed at enhancing the quality of the segregated coarse fraction, rendering it more suitable for bulk reuse in off-site applications. The efficacy of FRT in reducing fine fractions and mitigating leachable contaminants was assessed, with particular emphasis on compliance with regulatory reuse limits. The FRT process facilitates substantial reductions in key parameters, including fine fraction content (60–68.8%), dissolved solids (22.8–52.4%), leachable heavy metals (15.5–92.9%), moisture content (50%), organic matter (54.7%), electrical conductivity (45.8%), and leachate color intensity (55%). While the FRT method significantly improved the overall quality of the segregated coarse fraction, the resultant material does not achieve the regulatory limits for unrestricted reuse in off-site applications. However, the enhancement in material quality suggests that with appropriate control measures, the segregated coarse fraction can be considered for reuse in controlled or isolated environments. This study offers key insights that could inform municipal authorities and policymakers in revisiting the current protocols surrounding the rapid trommeling of legacy waste and supports the adoption of more robust and effective treatment methodologies capable of producing higher-quality segregated fractions for off-site applications with minimal regulatory oversight.