Accuracy is the base layer
A higher WPM is less useful when the learner spends the same time correcting avoidable mistakes. Accuracy-first training makes speed more reliable.
Weak keys need targeted attention
Repeated errors should become short correction drills, not another random test with the same problems hidden inside it.
Measure progress properly
Accuracy, WPM, error patterns, and consistency together give a better picture than one headline score.