> it is possible that we'll find relations that carry across the entire double-SHA-256 pipeline

Bitcoin mining is a partial second preimage of 0x00 though, not a collision, that statement just seems to be so outside the realm of what they’re claiming to have done. Even MD5, the most widely known to be broken hash, would be secure when used in the same way bitcoin uses SHA256 (other than being too short now, bitcoin miners have done 80 bits of work at this point many times over).