Customizing the concurrency per listener sounds an obvious feature but the namespace only allows to do this per jms:listener-container (that is, every listeners in the same containers get the same concurrency). The only way to get around this is to have on listener per container or fallback on an abstract bean definition (i.e. not use the namespace)
As @JmsListener is aligned on the namespace, it suffers the same limitation.
The purpose of this issue is to add a concurrency attribute at the listener level (and on the annotation).