Unfortunately this thing is about as viable as human powered flight. The battery weight makes up something like 50%+ of the gross weight alone, which doesn't decrease as you consume energy and there's no opportunity for energy recovery like in cars/trucks. Aviation is just a really poor application for electric propulsion.
The intended production version is a hybrid arrangement with pt6 turbines replacing two of the electric motors. I still have questions the viability of this arrangement as you still have the same problems as full electric with the added complication and weight of multiple power sources. But this full electric prototype feels a bit investor bait-y.