glue joints

I have one of these bevel cutters and it works really well. I've never really liked A and B folds so for my next plane (a pusher Hangar Simple Stick with FPV) I thought I would just cut bevels for the square profile body and fold it up. It sure was quicker and easier to build. Has anyone else...

In the process of building an FT Old Speedster, I came out with a rounded and ugly "B" joint on the top deck. Is there any good and easy ways to correct this?