I have a kindle 6".

The problem is that I often read pdf files that are technical, therefore, it doesn't get converted very well to kindle's native format (for example, code blocks get messed, and things like that). When I view the pdf page, it's very small to read easily, so I have to rotate the screen to a horizontal position in order to see it better, but my page get divided. But some documents would be easy to read in vertical position if I had the chance to enlarge the font size a little bit in a external pdf editor, therefore enabling the reading in the vertical orientation.

Has anybody had the same situation? Is there a solution for that?