Practical limits in @CalcMgrMDXDataCopy

Do you know about any hard limits on the amount of information that can be copied at once? I'm especially concerned about concurrency.

Say I have 10 MDXDataCopy instances running in parallel, each with roughly 500k cells.   If a copy fails with a loud bang! and logs something, thats OK. But if it fails silently then I cannot trust it to always copy 100% of the data I throw at it. 

Would tuning the JVM in opmn.xml help in this case?

Regarding the "max rows per page" parameter:

If I set a limit of 1000, logs show it's correctly paginating the MDX query results, but according to the docs this number controls how often to trigger the copy operation (that is every 1000 rows). My colleagues OTOH report that only the first 1000 records are actually copied, the remaining rows are extracted but never copied (confirmed this by enabling the log for the RUNJAVA command)