In a recent research paper out of Austria, Benedikt Mitter compares the validation of velocity monitoring systems across the Squat, Bench Press and Deadlift.
Not all Velocities are created equal. GymAware <0.15 Standard error (SE). Accelerometer based systems have more than 3 X the error.
Research by Benedikt Mitter April 2019 University of Vienna, Austria Read the paper
Have you made use of the cluster, work and rest timers?