2 pages side by side on landscape, a must for pdf.
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multiple columns per page, at least 3 (better 4) on landscape and 2 (better up to 3) on portrait, similar to scientific pdf papers for epub and maybe reflow pdf
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For me this is a must, I can't use neo reader without this features at all, it is a waste of space of the screen. You end up with ultra giant fonts for blind people or with tiny fonts but every line so wide that it's easy to lose it when moving to the next or trying to read fast.
When you can use columns, you don't need to move the eyes on the same line, with a fixed eye you can read a whole line and move to the next one much more efficiently.
Also, 2 pages for pdf in landscape with this screen is perfect and help us to avoid going back and forward so much when reading some technical pdf where you are referenced to other lines, pictures or graphs on the next page or the previous one.