Thank you Noel and Matt!

I ended up just transposing the melody. And it turns out

"Melody | Edit Melody Track | Transpose | Transpose Melody Only"

allows you to select a chorus number to transpose, rather than bar numbers.

Usually I unfold songs but in this case I didn't.

While I was tinkering around with it I unfolded it, then changed it back to having choruses -- I'm not sure exactly what I did but it created a bunch of extra bars at the end of the song. However it doesn't play them.

The song has 16 bars x 4 choruses for a total of 64 bars. Then it tacks on 4 bars at the end for a finale. There were notes in the finale, and extending out past that I'm not sure how far. More than 100 bars.

I manually deleted the notes in bars 65 - 68. There are still notes out beyond that but it stops at bar 68, so I'm just going to ignore them.