I learned how to manually create a gigapixel image the other day without a fancy gigapan machine. You need a panhead with alt and az labled and you must carefully zigzag rows with a telephoto lens and the pan head. I have messed around with the ghost image setting in ml and it i was wondering how many ghosts a camera like a 600d could display at once? It would be nice to fill the lower portion of the screen to keep track of row and column progress. What would really be nice would be a way to calculate sensor size, focal ratio, and card space and use this data to mark a starting and ending point XY axis to work on a gigapixel image. Here is a link to the page that brought about my curiosity http://blog.chasejarvis.com/blog/2012/11/how-to-shoot-a-7-gigapixel-60-foot-wide-photo-in-5-easy-steps-the-devil-is-in-the-details/
Hmm Id would like to add one more suggestion. 600d has no level and I know its not possible to add a level feature but, if I manually level the camera with a hotshoe bubble level would it be possible to place a line in the center of the live view screen that could calculate how many degrees you pan upwards from that line, or would it need an altimeter? Not sure if possible but this would all tie together for creating gigapixel panos. Regardless I'm sure there is some way that magic lantern in some way shape or for could speed up and make manual gigapixel panos more efficient out in the field. My suggestion is to try for yourself and maybe come up with more recommendations.