Any source of IMAX movies in 1:1.43? - Feddit

Hello, as the title states, i am looking for some IMAX movies (particulary tenet, oppenheimer and the dune movies) in their original aspect ratio (1:1.43, not 1:1.78). They aren’t availible on blu ray, only in the DCPs. There’s one guy on reddit claiming to have the files, but the other users were rather doubtfull. Do any of you know if and where such files exist?