Thanks! I ran the restore-set (really, with your modified Reader app, there's no more need for me to root...
) and installed the new version. All went well, the font-size setting works well, but...
The app needs to refresh after the button-hold multiple page flips. When you press and hold the prev or the next button, the page keeps flipping in black-and-white (non-greyscale) mode, and when you release the button, the flipping stops and the stock app refreshes once to bring the proper greyscaled display back. This version of yours doesn't. I guess this is the same kind of problem as the extra refresh after coming out of zoom?
As for the partial refreshes, I found that the count is exact when I flip the pages with screen swipes only, but not so when I use the buttons. If my setting is 6, and I flip the pages with just the next button, the full refresh comes at 6, 11, 6, 5, 6, 6, 9, 6, 5, 5, 10, 6, 6, 6, 23, ... This randomness continues even if I go out to Home and come back to the book. And then there are the occasional two-page flips when using the button (latest Sony firmware bug). I don't know if the two are related, though.
Regardless, this modded Reader app really makes my day.
