@
julo 
I assume your batch script goes something like:
Code:
ebook_convert
if a cover exists
ebook_meta add the cover
try adding
Code:
else
see Running from command line in Modify ePub Optional Plugin (← click)
to remove the cover that the convert put there
(set options for Modify in the GUI)
Then you can use a search in the GUI for cover:false, and do whatever with built in Gen Cover, Gen Cover PI, Cover download, or roll your own with your favourite image editor.
BR