MobileSheets from Zubersoft manages manual and auto scrolling very well - if you use Windows or Android. Many options for setting scrolling parameters, how much to scroll at a time, speed of scrolling, length of pause between scrolls, scrolling across multiple pages, scrolling to match the time to play a song. Scroll settings can be set for each individual score - it's extremely configureable. For more information download the manual from Zubersoft. I personally don't use this feature because my screen is large enough to display one page at a time, and I advance pages with a bluetooth pedal.
Phil