What it requires. A Loop element whose body only assigns values onto each item should use a Transform element instead. Transform operates on the collection in bulk, removing per-item iteration and the complexity that comes with it.
Why it matters. Element-by-element iteration is the slow path the platform has already replaced. Transform does the same work in bulk with less to read and less to maintain.
How to fix it. Replace the loop and its assignments with a Transform element mapping the source collection to the target collection.
Source. Lightning Flow Scanner, transform-instead-of-loop
Is this rule worth checking?
Votes and comments are published here. We read them, and we publish what we change with the reasoning — a vote does not move a rule on its own.