For me the "Page Overlap" is too intense, I would like it more transparent. I seem to remember some talk of some way to adjust that. I haven't noticed the first line problem, but then I have only used that option a couple of times just to try it out. I haven't had trouble finding where the new part of the page starts, with it turned off.
Most of the PDF manuals I have on hand came from
here. The First Aid and Engineering Manuals and Tech Manuals are looking great in KOreader on my AuraHD.
Luck;
Ken