Yes if you really want to compare you basically have to downsample from the hirez versions yourself .
The "same" song sold on different media at different times can all be slightly different masters especially the token CD layer on some releases , not to mention downloads and streaming services. There are to many unknowns to make that a valid comparison imho.
I'm holding these beliefs nowadays ( i do have hundreds of DVDA discs and hirez downloads so it's not that i haven't tried )
* 99.99 % of important contents is not hirez anyway ( audiophile labels may offer real hirez , but of no significant market penetration ). No, DSTM or kind of blue will never be hirez
* The chosen master is so much more important than delivery format that i do take the mp3 if thats the better master than the DXD or 24/192
* the really cool unappreciated thing with SACD and DVDA was the lossles discrete multichannel content it can be absolutely stunning.
* In the current world i think the industries should just pick 24/48 and stick to that to be the end format until humans evolve better hearing, it gives enough slush margins for sloppy engineering along the way, good ol reedbook cuts it very close to technical and human marginals .