Just about nobody has gotten anything accomplished with a grievance since 2016 when you started with the agency. Grievances, if they are filed (they are strongly discouraged by the union and FAA), are resolved now at the first or second level, which is within the facility level. There has not been one that has gone to arbitration, or even PAR (pre-arbitration review), in years. This is a byproduct result of the collaborative era. FAA and NATCA work together on all projects and processes, then in turn work together work to crush any challenges to the projects, processes or ideas, and they both own the process in place.
It sucks but the way it is, as the years go by you will notice more and more that you (or anyone else) has no say in. The contract was just extended for 6 years without a vote or any feedback from the general BUEs for example, and an entire NATCA E-Board was sworn in for three years, also without one vote.