boiling it down to the painpoint:
I wonder, if sub-processes can end with a message end event. And in addition, does this hold for event sub-processes as well? (I know that event sub-processes are not allowed to have boundary events.)
The standard does not really talk about this as it seems to be allowed, but that would mean that a subprocess sort of crosses its boundary with a message flow. And looking for examples I literally did not find any on google.
(My process needs to be able to react to input that can "happen" at any time. And after dealing with it, I want to send a message to another pool. Image sth like an event sub-process that listens to a process abortion from another pool (message start event), will process it and then send a message to the other participant "I cancelled it." ... )