I would like to see the ability to set Cover Art for Genres as well. For both Audio and Video, I think it would be useful. There was a similar discussion in this thread:
http://yabb.jriver.com/interact/index.php?topic=87765.0 See my Reply #10 for a work around where you basically use the Series Field to fill your Genre. This is definitely not a clean solution, but it could work for Audio since the Series Field is not typically used.
Just enter =[Genre] into the Series Field.
Then and save whatever Images you want to use in C:\Users\XXX\AppData\Roaming\J River\Media Center 19\Cover Art\Series. Name them appropriately so MC will pull them (ie Rock, Reggae, etc).
Now, in your Customized Views, change Genre to Series.
I believe mhwlng's Remote Control Web App (
http://yabb.jriver.com/interact/index.php?topic=86411.0) has a way of using Genre Images also.
http://yabb.jriver.com/interact/index.php?topic=85292.0 This wouldn't change your Views in Standard or Theater View, but would give you what you want to see when using a Web Browser to control MC.