[Geoff Bacon]

I used to have this problem because I used very long delays (150ish secs). As the bottom of the page loomed, I never knew if I had started the scrolling,

I have now changed most of the few songs that scroll so that they display a button about 2/3rds down the screen (caption Scroll, set to start/stop scrolling). This, with a short delay makes it fairly obvious if it is not active.

You could just use a touch area to toggle the scrolling but, as most of my songs are single page, I forget which area it is.
Also, the button acts as a reminder to start the scrolling. If required you could use a button and a touch aea to control scrolling.

Geoff