I'm trying to find a good way to control the Filename for X12 Acknowledgement files, but there doesn't seem to be a way to do that without custom coding. Here's what I figured out so far:
EnsLib.EDI.X12.Service.FileService allows you to set a Reply Target Config, which would likely be an X12 File Operation. The Service doesn’t have any settings related to the name of the Acknowledgement file though. That’s determined entirely by the Operation.