Hi Denver !
I solved this problem. I'm planning to post new image on this forum, soon.
I patched coolreader3 to do full refreshes after chosen number of pages. It is really similar to FBreader.
All source codes are on my git-hub page:
https://github.com/marek-g. I had to change kernel and add write permission for every user to fb0 device.
Best Regards,
Marek