I have a backup of Just Dance 2014 in wbfs, 4.3 gig. It works flawlessly.
Recently I had to format my drive to fat32 from ntfs, for unrelated reasons to this. So, I used Wii Backup Manager to split this file, it ended up to be a 3.99 gig wbfs, and 104 MB wbf1. (fyi I have other files like this...