I'm not sure I understand the issue you are having?? Whenever Marvin gets to the end of a file (likely at the end of each chapter) you have to touch the screen to get auto scroll moving again. You also tap the screen to pause auto-scroll and then have to tap it again to get it moving again.
Is the issue that you have to touch the screen at the beginning of each chapter? You'd rather it continuously scroll through the entire book? If that is the case, then I don't see why Kris couldn't add a switch to the settings for vertical scrolling mode to get it to auto scroll into the next file. I don't want to put words in his mouth though. He is probably wading through tons of suggestions.
In any case Kris requested in
this thread to send bug reports to him in an email. He is much more likely to follow up using that venue than here on MR.
Good luck - that sounds like a good idea!