Right now there are several "homegrown" caches in Jackrabbit. Some
configurable, some based on soft/weak references. Using JCache it
would make it possible to leverage existing caching implementations.
This could help in making the caches better configurable and tunable
and have features like overflow to disk, which could help with large
transactions, persist caches to disk during restart for cache warming
and clustered caches. For example it could be interesting to share
bundle/item state caches between cluster nodes.