I do not think that there are any non Adobe apps that make full use of Adobe sidecar files.
Thanks. I don't know of any either, but hope maybe I there is something I don't know about.
The xmp file is purely a simple text instruction set recording the position of every slider control position in ACR/LR.
Yes, this is why it seems possible that some other app could attempt to read the recipe and estimate settings required to emulate the previous conversion.
Another application would need to copy the Adobe algorithms and follows the Adobe pattern and order of operations to succeed.
Yes, but ACR doesn't seem to have an especially complicated combination of parameters. I imagine that the processing is more similar than different on the basic parameters such as color balance, exposure, contrast, highlight/shadow recovery, and white/black point.
I would be happy if something could start with that sort of limited emulation.
Thank you.