I have been exploring this type of usage as well.
I think it starts to encroach into the CMMN space.
If we were to look at something like:
Where the Start Event is used as the parent process to “Start a long running instance”, and you have Message Events in Event-Subprocesses that that append data to the currently running process. There are a few other ways to model this such as using a loop and Event Gateway, but That starts to get messy.
If a Message Start Event could have a self-defined form key it would allow a external system to detect the form that should be filled out to submit that specific message (assuming that the message has a series of variables attached to it.) But again this seems like CMMN would solve this problem, BUT adding CMMN also seems like extra overhead.
Thoughts?
@aakhmerov