Low aspect ratio wings have distinct advantages and disadvantages, Cl(max) being a large one that is more complex and/or heavy to achieve in a higher AR design.
It's a pretty clever approach to a number of ideas for a range of reasons not yet mentioned.
The aircraft essentially exploits a blown surface approach and the AOA is no longer merely a function of the angle of incidence but the power as well. This is well documented in the reports from the flights.
My models use a rectangular Clark Y wing section with similar effect and takeoff vertically at a wing incidence of 45 degrees with a thrust line incidence of 20 degrees. In this configuration, pitch control is maintained with the tail surfaces still, albeit very marginal at the moment. Directional control is difficult until established in forward flight, but is mitigated by using a single ESC for both motors. Directional and pitch control are impossible s the thrust line incidence goes beyond 20 degrees (slipstreams too far inclined away from control surfaces).
My dreamy napkin calculations indicate that, scaling from my model, a twin engined, 200HP total design weighing 1400-1450 lbs would be able to take off vertically at a 6000' DA (with 200HP available) with approximately a 5% lift margin, or take off at 20mph in under 100' with a 9% margin at Cl(max) at that speed.
My only plans for this spring for the model is to add a pair of RC truck differentials to explore single engine operation after an engine failure. A differential is a torque mixer, essentially, and the link between the two does not rotate when the torques are equal. If the ESC's are set the same, then torque at the command RPM will be equalized, and perhaps the cross shaft could be monitored to make engine power adjustments.
