I use those old finger-jointed yard sticks that Walmart sells and have never had one separate. BUT..... I don't do all kind of maneuvers like most folks do.
On a Deb trainer you should be ok. I *do* put a shot of thin CA on the finger joints on the yardsticks to help stick them together. I bet if you ran a bead of thin CA down the length of your yardstick and just let it soak in, the CA sticking the fibers together plus the torsion/tension or whatever it's called that the engineers in the group speak of that the gluing of the spar to the wing skin....... you'll be ok on a Deb whatever maneuvers you decide to do.
And if the spar snaps, chop the throttle, drop it on in, repair whatever happens and give it another go.