1. Create a new Blurb book with the default size, Standard Landscapes 2. Pick a page, and add a new cell to it. Photo cell or description cell does not matter. 3. Change the book size, say to Large Landscape 4. You get a message "Your pages will be migrated to the new size, but positioning and layout will change. Some existing content may not fit and will be removed." 5. The cell you added will be deleted.
Result: You lose your work.
Expected: Keep all the cells, scaled to fit the new page.
Workaround: None. You lose your work.
Note: The current resize algorithm is complex and wrong. It seems to remember the original page layout and revert to it. Nobody wants that. It is a bug.
The correct behavior is simple. I assume that each page is represented by a data structure that is a collection of cells, and that each cell has coordinates. If the coordinates are zero-based to a corner, then after resizing the new coordinates should just be multiplied by the ratio of the relevant sides.
A standard landscape book is 10 x 8 inches.
A large landscape book is 13 x 11 inches.
If a cell on a standard landscape page has coordinates (x0,y0)-(x1,y1) then you just remap them to (x0*13/10,y0*11/8)-(x1*13/10,y1*11/8). [At the risk of belaboring the obvious, the math needs to be done in floating point, so something like (int)((double)x0*13.0/10.0 + 0.5)]
This will preserve all the cells on a page. Yes they will have a slightly different aspect ratio, but they do under the current buggy algorithm as well.
There are other problems with changing book size. For example, photo text loses some of its attributes, like font size and Above/Over/Below. It would be nice if you fixed those, too. But these are secondary in desirability to the cell rescaling, because changing photo text attributes is mindless, whereas recreating all the new cells, re-finding their content photo, and rearranging everything is precise, finicky, and time-consuming.
I made a 315 page book in Standard Landscape when I wanted Large Landscape. Resizing it not only truncates pages (bug report) but also loses cells as described here. There is no 3x3 default layout, so I create that a lot, and other different layouts, all of which get lost in a resize.