as far as I know the dosBox version available is still not "finished", have a look at
this thread and
this post in perticular.
in short: if you use the "retain aspect ratio" option of dosbox to get the correct aspect ratio in the first place (4:3, no black borders at bottom or top, but black bars at the right and left side) nub input and touch screen don't work any longer.
I'm still hoping Pickle may fix that some day
Beeing able to stretch the video out to full screen (16:9) would be a nice add-on indeed. With many games the streched display is no problem at all and give you much better "readability". Nub input and touch screen would have to be adjusted for this option again, of course.