You know, I cant find a tool in Illustrator to "push" (bulge) a closed path (shape). The closest is putting another copy of the object behind and putting a large stroke on it, which distorts when you get to larger inputs. If your not familiar with push, I mean to expand the shape so that it doesn't scale, more its shape…
I'm surprised nobody has said to push the cage out more so it completely encases the high poly. Manually pushing out the verts around the problem area should fix it.