For instance, Rutan's Solitaire and Steve Wright's Stagger-EZ. What are the benefits of having a dihedral on the canard?
It seems like the canard dihedral increases yaw instability, and requires a bigger vertical stabilizing surface. Yet there are flying GA airplanes and sailplanes using canards with dihedral, and they've surely thought of this. What's the reason for that?
(My opinion-based hypothesis is that it's about very stalled AoA behavior, where canard dihedral may naturally slow down some flat spin, and help with recovering from it; still, I cannot find any references about this, and it may also be a very wrong statement as long as it's opinion-based.)
Edit: Gripen also has dihedral on canard surface, however since those are full moving surfaces with high sweep angle, depending on the angle of attack, those surface viewed from the front, display either dihedral, no dihedral, or anhedral (if very positive canard AoA)