Sorry, I got a little lost. Are you using a Convoy?
As far as parallel processing, direct binding is the easiest way to do it.
You can always create a single Orchestration that then starts as many other Orchestrations as that message needs. So you only have one subscription and then can start many Orchestrations (I have a sample related to this that I’ll post soon). You lose some flexibility and performance will be impacted. Does that make sense?