From the Kay Erdwinn’s Post Teaching Yoga for Round Bodies
Here’s another asana in which the abdomen gets in the way. A partial solution is to practice the variation with legs wide apart. One still has to turn the torso before bending over the knee, so some compression is inevitable. It’s easier than the standard, legforward version, however.
A word of warning: if the student is very large, the displaced abdomen could pull the back out of alignment, so that a slight turn of the back (seen as the outside shoulder dropping) occurs. This can be solved by making sure that the student turns the torso while still fully upright, and that the student adjusts his/her belly until it is squarely on top of the thigh over which the bend is to occur (see me above).
One simply has to be vigilant to make sure the student stays in alignment and backs off if needed.