[rfog]

Hello all!

I'm looking for a PDF reader that:

A) Write annotations inside PDF in standard PDF annotation format.
B) Compatible with eInk without screen flickering, scrolls...
C) Any way to sync across Dropbox (it must read/write direct into Dropbox or I can use FolderSync to sync my changes).

I've tried (and blocking problem, "scroll" means that is not possible to make page change without flickering/slow scroll, "tap" means is not possible to advance page with a "tap"):
-Stock Neo Reader 3: Once a PDF is open, it uses its internal cache and is not aware if PDF is modified externally (via FolderSync, for example), even if you close it and reopen.
-MoonReader+: does not annotates inside PDF.
-FoxitReader: scroll, tap, saves every time after opening a PDF even if you haven't modified it, and takes a lot of time to save it.
-Adobe: scroll, tap
-PDF Reader (from PSPDFkit): scroll, tap
-KOReader: extremely buggy, autisms, crashes (so buggy I've not had time to check if it annotates into standard annotation PDF way)
-FBReader: does not annotate, does not have list of annotations

Are someone using a PDF viewer with annotations that will be able to work smoothly with an eIkn device and have the things I want?

Thanks in advance.