I have been flying my Perigee for over 5 years now, built from the AAM plans. With the engine bearer design, and using rubber bands to hold the wing on there is no need to `beef' anything up. I can see that without the bearers, and going to the `modern' but heavy radial engine mount and bolt on wing thing then some redesign needs to done, but it will be heavier and weaker, and you need to keep the thing light. Don't mess with a good design.
Evan.