From the Kay Erdwinn’s Post Teaching Yoga for Round Bodies
I don’t teach this asana for the same reason as I don’t teach Halasana. However, the primary difficulty for a fat person in this asana comes in placing the hands on the back and the elbows close enough to the body to provide proper leverage. The strap-around- the-elbows strategy mentioned for Halasana may be helpful.
Other than that, the difficulties for the novice fat student would be similar to those of a thinner one, and therefore practicing with a chair or against a wall might be appropriate. As in Halasana, the caveat about large-breasted women having difficulty breathing also holds true here, as does the note on using blankets.