you can also use "add point" on either side of the corner point, then delete the corner point in the middle.

When you add point, it can be added "ON the curve" or "ON the Weight line". You want to add it to the weight line.

Also, you're getting deeper into your model before you solve your begining surface creation. If you start to jump around to fast and to much, it will get out of hand. Just a thought.