I've been exploring the Copy Chords and/or Melody function. There are a lot of useful options here.
I have a question about the [_] Copy_Lyrics checkbox.

I am using Bar Based lyrics. My experience is that it copies the lyrics regardless of Copy_Lyrics checkbox being On or Off. And after the Copy the Undo will remove the Chords but will not always undo the Lyrics.

To reproduce With a simple song ( No intro. 32 bar chorus, from bar 1 to bar 32. Repeat x3 choruses)
{I attached the song in PNG, rename it to SGU extension} maybe easier to enter the song than futz around with the png/sgu
[Chords]
|:a) C| D| E| F| G| A| B| C|
| C| D| E| F| G| A| B| C|
|%|%|%|%|%|%|%|%|
|%|%|%|%|%|%|%|%:3X|end) C|
[ChordsEnd]

and simple bar based lyrics
Bar1 lyrics
Bar2 lyrics ...
Bar16 lyrics

at Bar 25 try Copy Chords From 1, 8 chords, To 25
1)
With [_] Copy_Lyrics = Off
and [_] Copy 1st Chorus to whole song = Off
; Chords and Lyrics copied to Chorus 1 Bar25-32
; Undo will remove the chords from bar25-32 but will not remove the lyrics

2)
With [_] Copy_Lyrics = Off
and [y] Copy 1st Chorus to whole song = On
Unfold to see the other Choruses
; Chords and Lyrics copied to Chorus 1 Bar25-32, Chords only to Chorus 2 & 3
; Undo will refold, then remove the chords from bar25-32 but will not remove the lyrics

BIAB Win 2021 Ver 838

thanks Roy
Toronto area, Ontario, Canada cool

Attached Files (Click to download or enlarge) (Only available when you are logged in)
16 Bars 16 Lyrics(rename to SGU).png (38.56 KB, 56 downloads)