Hi Peter, heres an example what i think would work better on stage when selecting Lyrics only track, i have purposely used a light background and a bright surround to easily destinguish between audio backing and lyrics only tracks , this should really help using smaller devices.
And a nice solid darker colour bar to see where you are at a distance that dims the brighter background as it progresses to the end so at great distance you can easily see your position in scroll. Hope this helps to prompt even better result.

Here is another light bulbe suggestion and follows the looping idea.What do you think!

This would allow you to use your auto play as normal but give you the freedom to go to any important place in the song QUICKLY to arrange your performance on the run. FREEEDOMM!😀
Perhaps this same idea can be used in PDFs as well so any song can have up to 6 pdfs and quick access to the pages.