It is an intentional design decision. Some people use the same song with different themes, theme A may have room for 8 lines, theme B only room for 4 lines due to the background image.
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They don't want to have the same song twice in the database, so they can suggest the best place to perform the slide break for theme B using [---], however keep a long verse intact for theme A.
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To force a slide break, we made it so you can just specify the same verse tag more than once, as per Raoul's original reply, so your scenario is equally possible.
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