Thank you very much. I tried it out and it is substantially better. Depending on the images you can sometimes still see a bit of ghosting but I think this workaround killed about 75% of it.
Suprisingly it works only when I try it with real Mangas. When I use the test patterns (uploaded
here) that I made for testing and checking which orders are the most vulnerable to ghosting and how to make it go away I see almost no improvement.
The worst case is pattern 1 or 2 followed by black. A pattern followed by white also has some ghosting but much less than with black. Inserting white between pattern and black removes the ghosting in black. Everything tested with the light turned on to 25 %.
I personally would not need the white page workaround to work with screen rotation. I would only need portrait mode and inverse portrait mode because I use two inkpads next to each other in a custom cover that I made out of two original ones (114 kB image:
https://i.postimg.cc/mgjZFjrv/CIMG4162.jpg). This works almost like a real book. So double page illustrations are not shown horizontally but split over two devices.
The only drawback in this case is the huge border between the two image parts.
At first I had only one inkpad but after some time I got the second one very cheap because it was sold as defective. It turned out that it just had an almost completely discharged battery. And the covers were sold for 5 bucks a pice.
When my pocket allows it (not in the near future
) I might upgrade to two Kobo Formas, they have a much thinner bezel, newer screen technology and less weight.