Among the key design practices which contribute to the development of inclusive ICT products and services is user testing with people with disabilities. Traditionally, this involves partial or minimal user testing through the use of standard heuristics, employing external assisting devices, and the direct feedback of impaired users. However, efficiency could be improved if designers could readily analyse the needs of their target audience as part of a highly iterative design process. The VERITAS framework simulates and systematically analyses how users with various impairments interact with the use of ICT products and services. Thus, facilitating an efficient approach to design and testing. This article reports qualitative insights into the use of the framework by 72 evaluators drawn from five application domains: infotainment-games; workplace design; smart living spaces; healthcare; and automotives. The findings show that the VERITAS framework is useful to designers, offering an intuitive approach to inclusive design. However, several key areas present challenges to designers; notably, their lack of technical knowledge made the interface difficult to comprehend and their lack of familiarity with virtual user modeling or simulation software made the workflow difficult to follow. Furthermore, designers had a number of expectations in terms of features and feedback which were not fulfilled. This article reviews these concerns and presents recommendations which will inform the design of future inclusive design tools.