I haven't had any luck finding a fix for the FullScreenReading refresh bug, but I have an idea how to make the old-style ePub full-screen mode (i.e. normal mode with the reading footer disabled) a bit better for those who use adjustable top/bottom margins.
On the Glo, the ePub reader has a built-in top margin of 15 pixels, which is 2% of screen width. I'd like to find out if this is the same on other devices.
If anyone wants to help, you can sideload
this test ePub and take a screenshot of the first page in
normal reading mode, not full-screen mode. It should draw the biggest rectangle that can fit on the screen. I just need to know the number of pixels above the top of the rectangle.
Don't use Calibre to sideload the ePub if you have anything that automatically changes the stylesheet, just copy it to the device instead.
If you have the fixed/adjustable top/bottom margin patch enabled with adjustable top margin, then set the margin slider to minimum before taking the screenshot. If you have a fixed top margin set then let me know what size you have set in the patch. Otherwise if you don't use that patch then you don't need to do anything else.
Edit: Attached is the screenshot from my Glo, just so you know what to expect.