All known issues are listed in the Apache JIRA. Changes with respect to Jackrabbit-core are collected in OAK-14 and its sub-tasks.
Cross workspace operations are not implemented yet See OAK-118
Workspace Management (creating/deleting workspaces) is not implemented yet See OAK-118
Observation queues handling
With an excessively large commit rate, the observation queues can fill up and if not prevented and the queue hits a certain threshold and/or the limit then it would result in Local events reported as external event OAK-2683
Changing an observation listener’s filter:
Prefiltering of observation queues means that if an observation listener’s filter is changed, that new filter will only fully be applied to newly added changes to the observation queues. Those changes that potentially were still in the queue will have gone through both the old prefilter and the new (post-)filter. OAK-5208