I'd not seen this, I see they experienced issues for sure;
"The power limitations occurred in two places, cone rigidity and mass, and the thermal capability of the voice coil. At low frequencies the cone experienced structural modes that wanted to tear it apart (we affectionately refer to them as “taco” modes due to their shape) while the high currents in the voice coil cause it to overheat."
They should've applied what they learned to a follow up effort, that would've been interesting. Mucho larger VC, drive the cone at from a point further away from the center, examine some other cone material techniques, etc.
Just being picky, I do appreciate you sharing.