EXTVAL-57 introduces a meta-data storage. meta-data extraction interceptors were introduced in extval 1.x.2. they can dynamically manipulate the extracted meta-data.
the new meta-data storage allows a better performance. to manipulate meta-data once meta-data extraction interceptors would be an overhead.
so a meta-data filter for the meta-data storage are just invoked directly before meta-data gets added to the storage. so static manipulations also get in the cache.