All I want is normal production-ready crypto mattes in 2025. I have been waiting for them since 2018.
Can you explain in what way they are not production ready? They are just industry standard cryptomattes already. Now, it seems that Nuke (I think it was - one of the video editors anyway) uses some additional (not part of the actual cryptomatte) metadata and without that metadata, Nuke doesn't process it the way it would process things otherwise. Is this what you mean? Let us know so we can take a look into it :) But right now the cryptomatte from V-Ray and from Corona works the same in, e.g. Photoshop or Resolve.
PS or is it that it has to be saved to CXR, which then need renaming to EXR and the renaming step is what causes problems?