This one I'm calling Swimmer Wing, meant to be one of two sets of wings that counter-rotate with respect to each other, in a dragonfly format, for inertial balance.
In trying to figure why a bird wouldn't do it this way, there are two reasons; moving the wing forward and back is a waste of energy for the bird in the first place, and their body isn't usually long enough (or more precisely hasn't the inertia about the Z axis) to counteract this movement, so head and tail would snap left and right, and it's all very lossy.
It does happen to be convenient for my simplest single curved spar layout, where left wing is out of phase 180 degrees from the right. Again, for balance and not losing a lot of energy, there needs to be two sets of wings, and there are several layouts that get you this inertial balance, which I'm exploring now.
Of interest later is getting a pure inertial balance so a camera payload won't shuck around all the time, but that's not my concern at the moment. For now, it's:
Continuous spar
No guy wires
Continuous rotation of power source
Rigid wing skin
Smaller wings (dragonfly is great for that)
Viable aerodynamics no matter where the drive stops