Ashley, thank you for putting this issue under consideration! It is just a large issue for me as I am making a rotary gravity shifting platform game for the contest, and circular planetoids are central to its gameplay. Since the collision objects are so large, an octagonal collision mask does not cut it.
Hmm, I just came up with an idea... Perhaps I could instead make 'segments' with 3 or 4 points of collision, and they could be rotated around a single point in the editor. I suppose this would be a viable alternative.
Keep working on the important features! I trust your list of priorities completely ;)