Every item on your checklist should add unique value. If two items check for the same thing, you're wasting time and adding clutter.
Redundancy happens when items overlap significantly. For example, "Test all features" and "Verify each function works" essentially ask for the same check.
Remove or merge redundant items. Each check should cover distinct ground.
This keeps your checklist lean and focused. People are more likely to use a checklist when every item matters.
A shorter, non-redundant checklist is also easier to maintain. When you need to update a process, you only need to change one item, not several overlapping ones.
References
Scriven, M. (2000). The logic and methodology of checklists.