In recent years, the focus of microwave engineering has been on minimizing losses to improve system performance. However, recent research has demonstrated that engineered losses can enhance the performance of microwave components. This paper explores the application of loss engineering to reflective-mode phase-variation microwave sensors, showing how resistive losses can be utilized to achieve unprecedented sensitivity. These sensors, designed to detect small environmental variations, hold great promise for applications in sectors such as agriculture and food processing, healthcare, and civil infrastructure monitoring. By leveraging loss as a deliberate design parameter, this approach repositions losses from a limitation to a key element in enhancing sensor functionality and achieving new levels of measurement precision.