Thank you for reaching out to us with your question. I’d be happy to help with this.
I asked a member of our dev team for more insight on this. They recommended adjusting your preferences for Artwork to prefer best in your import settings. You can make this change by navigating to Settings>Library>Import settings and selecting Prefer best for Artwork as illustrated in the screenshot below.
Not disagreeing with what has been said. But I differ in two areas.
I have artwork set to “Prefer file”. I want the artwork to match the version of the album I have. Sometimes the cover changes between versions. For example, a MFSL cover is different from a standard CD cover, and the Roon search won’t normally pick that up. So I make sure I embed the right cover version in the file.
I prefer 1200x1200. No reason, except it is more or less consistent with what I do for movies in Plex (1500x1000). I kinda think 600x600 is a bit small if you actually want to read something on the cover, and the larger size does not seem to affect Roon’s performance in any way.
Thank you for sharing your suggestions with @Bill_J as well!
I also use 1200x1200 jpg as my personal preference for album art where possible. I’ve always liked seeing the MFSL band across the top of an album cover also!