I cut this air layer off about a week ago. The roots were growing out one side of the container after 3 to 4 weeks. After cutting, the roots weren't quite as many as I expected, but still nice, thick and white. I still thought it was enough to support the limb.
It started wilting about 10 minutes later. The next morning, all the leaves were hanging straight down, limp as a noodle. So I cut the fingers off of every leaf and hoped for the best.
After a few days, the leaf stems started perking back up. Then all the lower leaves dropped, the upper ones stayed on, but are dry and burnt around the edges where I cut them.
Those few upper leaves are now standing up normal and the lower part is now putting out new buds. Looks like it's going to be fine.