Next version will allow you to customize default file names using predefined patterns. A 1st beta will soon be availble. Make sure to join the Beta on the Play Store app page to test this and provide some feedback.
This will of course apply to new downloaded episodes only.
You will have to go to Settings/Download and press on 'Use Custom filenames' to change the default behavior
An error occurred while saving the commentPeter commented
I use the played flag as a downloaded flag to indicate whether I already downloaded it and have the file here or on a different device.