Thanks to user Phase3 for spotting a weird teal rectangle going across part of the top upper left of a transition between scenes at around the 28m mark I was then able to find the 35mm frame and note that the weird rectangle was NOT there in the original 35mm theatrical release.
This weird teal rectangle has been on all versions of AOTC going at least back to that, German I think?, HDTV broadcast that was captured (and probably it is on VHS then I’d guess).
So definitely proof of muddling around with things post theatrical. Almost looks like teal power windows brush hah. I wonder what the story with it is.
It is not the most momentous difference ever hah! And certainly not really the sort of ‘change’ you’d expect at all, looks more like a weird mistake of some sort that apparently got backed in super early post-theatrical (perhaps even for the digital theatrical?) and has been there for at least the whole HDTV through UHD release.
Also, assuming it was not there in the digital theatrical then it also proves that the UHD was also sourced from the same modified for home versions as all the rest and not a going back to an original digital master or anything (again, assuming it was not there in the digital theatrical and I doubt anyone would possibly remember that or have even noticed it if it was there).
And with the UHD also seeming to lack some of the wide gamut insane teals/greenblues found on the 35mm and the odd trace teal blue “A long time ago…” intro text even though UHD CAN show those colors it seems like the early home revisions might have accidentally (?) been done in REC709 and then they were stuck with that gamut unless they were to go back and re-do all the little changes for home??
Here is a snap that Phse3 made of one of the home versions:
And here is the original 35mm:
So what the what is this weird blue blob??: