Well it is a separate rocket version, it just doesn't take jet fuel. "Invite only" for the rocket version means probably less than 5 will ever be made, if that.
I strongly suspect that the invite-only version is the tech that was described in the demo, and differs from the $250K version by the size of the air tank and compression motor.
I strongly suspect that the invite-only version is the tech that was described in the demo, and differs from the $250K version by the size of the air tank and compression motor.