I'm active in a few photography spaces online and I don't think I've talked to a single person who actively uses one of those. Most people use Lightroom or Capture One, which are also not available on Linux.
I'm curious as to what value you get from OEM RAW processors.
Exactly (or almost) the same render as from SOOC images.
I hate it when I deliver SOOC preview images that the customer really likes, but wants some small tweaks (remove a fly from the image, for example), and the colors or contrast on the resulting image is different because I didn't use the same processing engine or color profiles.
From what I remember, Nikon RAW files don't retain any changes you made to them in-camera unless you remove them from camera using the OEM app.
(Things may be different these days. My knowledge is from 2015.)