Great software, cacapee!
When I was reading documents on my sony reader, sometimes I'd like to view it in a single page so I can get more content, but sometimes I think it's clear and easier to read if I split it into 2 pages.
So I have a idea, can you make a new mode, say "double portrait", the Height will be (600-46)*2=1108 or something like that, and the width will be 1108/1.29=858.
This mode will increase the size of final LRF file, but we can use the rotate function of sony reader itself to switch in different view rotation.
And thanks again for the awesome work.