My fear is that critical shards would be heaved radially and some of them would remain lodged in hidden crevices throughout my garage, and they would never stop whispering inane little complaints and criticisms, rendering the room useless for the purpose of painting.
I only rotate the canvas when doing so will facilitate stroking the outer edge of a curved passage. The need to do that in figurative painting is somewhat limited but every once in a while it comes in sooo handy. I rotate my canvas a lot more when I do these:
http://www.thefineportrait.com/fred.html