I can't think of much. As the plane stands it's capable of anything with no airframe mods. Some people have been making the channel that runs through the fuse bigger so the extensions can go through easier, but I did not have a problem getting mine through the hole. I would probably make the hatches out of a thin light ply if I build another, after 100+ flights my hatches are getting warped and lifting up. OR just make sure they are sealed up good when you put them on the plane.