A small amount of dihedral in a trainer, beginner or advanced, is a good thing. Look at your warbird wings. Too much dihedral is a pain in the butt.

Rubber bands are there to let the wing detach in the event of a sudden, unexpected contact with the earth. Extra rubber bands permit aerobatics. Bolts are good, but usually assure damage in the contact with earth situation.

Either method is fine, but both have downsides. Pick your poison.