Seems that 128 GB cards work too, to some extend at least. I now have SanDisk Ultra 128GB UHS.I card. It does not work as well as my 64GB card.

Both are formatted as btrfs and both contain same music files. I made symlink to /run/user/100000/media/sdcard which points to /media/sdcard and the file browser is able to navigate the files on card. Music player finds files on 64GB card but not from 128GB card.

There might be something different in those cards but I haven't had time to investigate, will report back when I have had time to fiddle with it.

Sorry for not creating own thread for this, should we create a separate threads for each card size?.