In v2.78 I tried to save LYRICS(synced lyrics) field into ALAC encoded files, but when I reopened the 'Extented Fields' dialog I found the tag name become 'UNSYNCEDLYRICS'.
I used another file whose UNSYNCEDLYRICS field was already present and tried to write the LYRICS field into it. Then there was two UNSYNCEDLYRICS fields.
This issue is 100% reproducible on my Windows 10 Pro x64 (Simplified Chinese) computer with v2.78 and the latest development version v2.80c.
I wonder whether it's a bug or a feature...I know that iOS devices don't support synced lyrics, but I still want other music players to work with it...I apologize for my broken English.