In the field of Business Administration, Management and Corporate Governance, transitioning small manufacturing enterprises toward closed-loop circular production models is hindered by resource constraints. This empirical investigation systematically examines Circular Business Model Implementation in Manufacturing SMEs: The Moderating Role of Digital Capabilities through a multi-stage experimental methodology and rigorous quantitative analytical framework. Utilizing moderated regression modeling based on survey responses from 410 manufacturing SME executives across India and Malaysia, data were gathered across multiple operational cycles and validated against established international benchmarks. The statistical and computational results reveal that circular design adoption significantly improved firm profitability (beta = 0.342, p < 0.01), with enterprise IoT capabilities strongly amplifying this relationship. Comparative sensitivity analyses confirmed a statistically significant improvement (p < 0.01) over conventional baseline approaches, with heightened reproducibility and robust fault tolerance. These comprehensive findings provide actionable theoretical insights and practical implementation guidelines for SME policymakers, industrial park managers, and circular economy consultants. Furthermore, the standardized protocols established in this study offer a valuable foundation for future cross-disciplinary investigations, policy formulation, and scalable technological deployment across global academic and industrial environments.