[pkscout]

I set the path to the parent folder of the artists in AS. Which is: SMB://WHS/Music/
I changed the setting in AS to use both local and remote images.

But I am slightly confused about how things are meant to be working?

If in the Aeon MQ4 skin, I have selected from the pull down menu - Art -> Extra Fanart turned off. Then the artist background images that are displayed during playback, are the ones that it gets from TheAudioDB.com when you load / reload the artist etc. These presumably are then cached locally somewhere on the HTPC.

If I then turn back on Extra Fanart setting in the Aeon MQ4 skin, it only displays the artwork images in the artists extrafanart folder (If present) on the file server. Not a combination of both.

However if an artist doesn't have any extrafanart sub-folder present on the file server, then in that case (even when extrafanart is turned on in the skin) it will still display the artist background image obtained from TheAudioDB.com.

You really need to find the Aeon MQ4 thread and ask there. The setting you mentioned is an Aeon MQ4 setting, not as AS setting, and skin developers have a great deal of flexibility in how they implement AS. I don't use the Aeon MQ4 skin, so I'm not in a position to clarify how it works with AS.