It's of limited help, but I haven't used the FiiO app in years (it struggled with my big library on my 400GB and 512GB cards) - I bought NeutronMP.
[I'm late to the party, whoops!]
I never had ANY issues with Fiio X5III and was able to download the player and updates. All of my files are lossless FLAC format and are loaded on the SD cards in folders by artist and then folders within each one by album. Album art is embedded on in the ID3 files as 400x400 folder.jpg files. If it's a compilation album with seperate cover art for each disc/album, I embed the individual covers in the appropriate ID3 tag and then put the main cover art as a folder.jpg file in the artist and album folder. The storage requirement for this was negligible and it never had an issue with displaying the correct album art. I was using two 500gb Sandisc SD cards with no issues. I did try LEXAR cards -they did NOT work. I always used the Fiio pure music mode unless I wanted to listen and watch a video. Then I used the Android mode and a third partyys video player app. I have always preferred the AKM dacs - I just think they are less analytical and more musical sounding. And it is all about the music!
Awesome. Thanks friend.
If you've got time to tinker, once it's in your possession, see my signature link.
