//It probably flew better with dropped wing tips due to the compression lift//
That was the theory, but in practice the dropping of the wingtips the airplane gained more by shifting the center of pressure forward, so much less elevator trim(drag) was required to keep the airplane level. At least thats how I understand it.
Compression lift did not meet its hype other than drag reduction I would guess. Ben Rich had some good words on it.
They should have finished the third bird, not scrapped it.
The miniature in the Smithsonian is the wind tunnel model for the third one, with the canards set farther back than the first two.