About Nikon corruption https://exiftool.org/forum/index.php?PHPSESSID=6a4657a4d4b3ceffb5cbdea55aabafe7&topic=4220.0
and
https://discuss.pixls.us/t/very-different-initial-rendering-of-raw-file-possible-corrupt-file-but-re...
I guess this part from the Rawspeed maintainer includes Canon:
As it has been said, nobody should ever use any program that modifies the original raw files for any reason whatsoever, including “harmless” sidecar embedding.
But I have never ever heard anything about raw file corruption due to DPP or EOS Utility.
One interesting thing is that DPP4 doesn't support new features, like ALO, in older raw files. So the "embedded sidecar" must be limited to already writable metadata fields for each camera model.
I will not have any access to a computer during a month so I can't analyze the metadata fields myself right now.
