I haven't finished mine yet, but one of the things I was told while asking around
was to reinforce the area under where the center struts mount to the fuse,
apparently this area is quite susceptable to breakage should the plane flip over
on landing. If you study it you can see why, the way it's designed to bolt to
the fuse creates a leverage moment at that point. You can easily reinforce this
area by putting some corner gussets next to the attachment point with very
little weight added. My other ultimate has the struts running straight down
parallel with the side of the fuse and doesn't have this weak point.

Motoaire.