You may have noticed that Oracle BAM 12c offers a new option on the Enterprise Message Source (EMS) configuration within the "Source to Data Object Field Mapping" called "Persistence Payload". Once you check this box, there is no more payload transformation required. This is because the payload has everything it needs to send you data to BAM 12c and perform the correct operation including the name of the data object that you are trying to populate.
You can use JAXB to programmatically build the payload that you need for BAM as shown in this example.
This will allow you to send via JMS batches of messages within a single JMS message. BAM will subsequently separate them into individual rows so you can use them within your BAM dashboards exactly as if they were sent individually.
But it allows you to send a much higher number of events than you could if you were to send them one-by-one.