Inheritance

When a destination inherits the prefetch property from parent destination with matching names, these behaviors are possible:

When all parent destinations set the value none, then the child destination inherits the value none.
When any parent destination sets a non-zero numeric value, then the child destination inherits the largest value from among the entire parent chain.
When none of the parent destinations sets any non-zero numeric value, then the child destination uses the default value (which is 5).