Batch insert of aggregates

I am using JPA event storage implementation of the axon framework. My database is MsSQL. I would like to know if the JPA event storage engine (with RDBMS database) of axon framework is production ready?
Could it be used for many millions of aggregates and 10 events per aggregate?
Will we have any performance impact if we do so?

Also to test the performance, I would like to insert 3 million aggregates (1 aggregate creation event per aggregate) to the rdbms eventstore by using jpa event storage implementation of axon framework. Is there any way to optimise this insert by using some sort of batch insert? Currently I am inserting it one by one which is taking lot of time. Any suggestions to decrease this time?