Ah yes. I've seen similar in college design competitions and such. I suspect such a design choice is still an anomaly because of issues. I would expect these to include;
- Manufacturability
- Fuel storage (remember, win
- Cost to provide long-term fatigue and behavior studies. If you want to put a design feature into a commercial airplane, you have to prove to the FAA it's safe, and that it will be safe tomorrow, and that you know how it will fail, and you know how to inspect and repair it.