Harmy said:

... the problem is that the best source that is likely ever to be available to us is a theatrical 35mm print, which most likely doesn't even resolve 1080 lines to begin with - the best you can hope for is to get about the same level of resolution as the official BDs

I'm confused about this. The detail lost in the generational losses between the negative and the theatrical prints mean that a theatrical print scanned at 4k or higher would be equivalent in detail to the negative scanned at 1080p?