Well, that may very well be true. I am willing to lose up to 4 frames in about two dozen shots, at the most. But in any case, it would be done digitally, not optically, they would just scan the stored originals and then edit them into scan they did of the SE in 2004, or just re-scan both--ideal, since the 2004 SE scan was only HD--but you could easily do a 4K scan of the 1997 SE and the stored originals, create a digital edit of the 1977 neg conform and then make home video and theatrical prints from that. I don't know if its even general practice to just print off stuff optically from the O-negs, at least when we are talking classic films here.

And, lets not forget, the O-neg was also irreversibly altered for the 1997 SE in its restoration--for the better. Some shots had faded so much that they were unusable, and I think there might be a couple of dinged up frames in there that had to be cut out. Its just the inevitable process of time. So if people want a true 1977 version made from the original pieces then you are shit out of luck, the film literally crumbled away like a yellow newspaper in some places, so you would have to make a "virtual" O-neg no matter what, by which I mean replacing damaged parts with lookalikes, which is what happened for the restoration, they took shots from the best IP/IN's available and put them into the O-neg to replace the damaged pieces.

If you really wanted to get hardcore about it, you could take the OOT IP's that they used to harvest donor shots for the restoration and retrieve the missing frames that might have been lost when conforming the SE neg.