This work explores the complex interaction between corner and gate fields in a Ge(1-x)Snx TFET-based bio-sensor, investigating the potential of corner-point—typically considered harmful in device design—for improving sensing performance. The analysis uses sensitivity performance metrics to develop design guidelines/approaches that focus on optimizing channel epilayer height (EpiH), nanogap cavity length, and corner-point necessity. A significant finding is the identification of a critical threshold at EpiH = 30 nm, beyond which the corner-point no longer enhances sensor functionality. However, the study reveals, EpiH = 30 nm should not be regarded as a fixed optimal value; instead, a range of design parameter combinations is possible, with the appropriate choice depending on the specific application needs. The guidelines provided are instrumental in refining sensor performance, ensuring reliable, efficient and cost-effective bio-sensors for accurate bio-marker detection.