I just discovered the following:
When I remove a converted image (the raw file, not a TIFF copy) from Lightroom, restart Lightroom and sync the folder that contains the file that has been converted and removed, the file has lost the conversion.
Even though the .xmp sidecar was saved before removing the file from Lr, the conversion was lost.
This basically means that all info about the conversion (including metadata) resides solely in Lr’s catalog and is not exported to the sidecar file.
b) intended and
c) can we do anything in order to preserve conversions under these circumstances?