this is supposed to be an internal synchronization mechanism and so it should not be configurable. I only use the ```concurrenclyLevel``` to avoid put some random number. Also, I don't use the ```LockManager``` because this locks are internal (as I said) and they are short live locks (in opposite to the ```LockManager```, that the locks lasts at 2 RPC or more and the user can lock a key indefinitely). 

As you said, I use a per-key lock to reduce contention. If you are worried about memory, I can set the lock container when we have ```cacheStore/cacheLoader``` and ```passivation```. In other cases, ```CDL.lock()``` will not do anything.