The v5.5.1 update is designed for "one-click" operations on MediaTek devices without requiring specialized "DA" (Download Agent) or "Auth" (Authentication) files for many models.
While newer versions often emerge, technicians frequently return to v5.5.1 for its that was ahead of its time. Many users find that it handles most modern repair needs so effectively that it has remained a "go-to" setup for years. How to Get Started ultimate multi tool v5.5.1