FeedWatch sending an export to a specific mixer is the December 2018 Tip of the Month.
The point of this task is to send an export ONLY to the desired mixer. Sometimes it is desired to send an export to one mixer and not the other so that it does not reset the schedule of the other mixer (if not using periods). There are times where you may make adjustments and only want them to go out the following day but need to use a backup mixer that current day. Excluding some particular mixers help avoid affecting current work flow of the feeder. Be sure that when you are done sending the export that you go back and re enable communication to the other mixer(s) so that they communicate with the office again.
To do this: Navigate to Setup -> Equipment. From here you can select or deselect which mixers you want to communicate with the desktop.