Following up on #35840, we could consider generalizing the resetCaches() method from CaffeineCacheManager / ConcurrentMapCacheManager into the CacheManager interface. Just like the current provider-specific methods, it could have "throw away the cache content" semantics either through cache clearing or even actual dropping of caches.
A quick prototype shows that this method may have a straightforward default implementation that just iterates over all registered caches and calls Cache#clear() on them, whereas concrete providers can have a more optimized implementation (e.g. for JCache) or a more radical implementation that actually drops caches (like we have in CaffeineCacheManager / ConcurrentMapCacheManager already). CompositeCacheManager can apply the call to all of its delegates, making this useful for a broader cache reset attempt in an application as well.