I was thinking about editing of lyrics will go about once the user has already synced a few elements and then decides to edit the lyrics and goes back to the editing tab? Could be any of the following

• Timestamps reset (Lazy fix - probably the easiest)
• Modified line reset (check for which lines have been modified and then reset those lines' timestamps.)
• VocalElement check (slowest and probably the hardest to implement - check what all elements have been modified, then map those)