E-mailed FiiO about the issue I had with the 'All Songs' menu showing the filename instead of the song title. Here is their response in case anyone is also wondering:
Thank you for your mail and support to FiiO!
Yes, we don't make the songs show the Song Title in the song lists, because some songs don't have the song title, such as CUE file. Think about it, if there are many many CUE files in the TF card, but users can't found them on the X1, and this situation will make users very confused.
So if any inconvenient, pls understand it!