I have to politely disagree with you there.
The bluray doesn’t contain any more detail than 4k77 with the exception of the area of the image that was cropped. The bluray is heavily sharpened which gives the illusion of additional detail but not any actual additional picture information.
I’ve sharpened the 4k77 footage myself as an experiment and it can be sharpened to match the bluray exactly.
So my question stands.