The "Easy Connectors" are as safe as any other connection PROVIDED YOU PUT A DROP OF THREAD LOCKER ON THE SCREW AND MAKE CERTAIN THE SCREW IS REALLY TIGHT. You need to redo the thread locker EVERY time you loosen the screw. If you use the thread locker you will have absolutely no problems with them.

Without the thread locker the screw can loosen.

In any case, even though they make them in a 4-40 size, I would not recommend them on ANY plane powered by an engine larger than a 60 2 stroke or the equivelant 4 stroke.