This study investigates systematically extracting strategic insights for improving assistive technologies for persons with disabilities, vital for their autonomy and quality of life, through clinical evaluation. This contributes to a more structured evaluation methodology. A questionnaire survey was completed by 35 individuals from targeted assistive technology companies. Additionally, 20 semi-structured interviews were conducted with stakeholders (developers, clinicians, users) representing 20 of these companies. Insights from clinical evaluations were qualitatively analyzed using Affinity Diagramming to structure key findings. Critical insights for product refinement were most frequently generated during functional and overall prototyping stages, enhancing functionality, safety, usability, and impact on daily living. Three key elements for insight generation were identified: (1) collaborative relationships between developers, clinicians, and users; (2) a rigorous and appropriate evaluation methodology; and (3) explicit recognition of evaluation limitations, fostering continuous improvement and realistic expectations. Effective practices included minimizing subjectivity and leading questions in user interactions, observing user reactions and emotional responses, and interpreting core issues from user behavior. However, some clinical evaluations lacked adequate prior safety assessments, a concern for medical professionals. These findings underscore the urgent need for concrete preclinical safety assessment criteria before clinical evaluation. Drawing on user-centered design and BioDesign, this study offers actionable insights for optimizing evaluation methods for specific development stages, and highlights the importance of including perspectives of individuals with disabilities in future research for more inclusive approaches.