Hey,
the option "Automatic save on render end" does actually save the CXR-file. So you just need to locate your corona history folder and you will find the CXR files there. Regarding batch-processing, which you want to do, I hope somebody else can chime in and help you out!
C:\Users\Admin\AppData\Roaming\MAXON\Cinema 4D R20_4FA5020E\corona\history
Was this helpful?
Cheers,
Ara