Make the document "Pan-able"
When I have an e.g. a4 sized pdf open on my XPS 2-in-1, i would often like to move the pdf freely around in the program i.e. if i have it at zoom: 50% the pdf is stuck at the center. On way to work around this is to add a big page at the bottom or the top of your document, and i can move the document according to the borders of the big page (e.g. a0) at the top. I hope i managed to describe my "idea" properly.
Another idea I think has been posted here is the option for indexing my files. I'm a student with several courses, and during a semester i might have 200 articles open in drawboard. I would love to be able to put them in "folders" or tabs according to the courses i take!
Last idea. A friend of mine uses noteability on his iPad, which has a great feature. While drawing a line, if you hold the end-point for a second it automatically creates a straight line. This is a very handy feature i would love to see in drawboard!
Other than a few details, i really love the software.