It’s esoteric but I want to preserve this information.

If you use sidecar (XMP) files in Lightroom, DNG files do not have a sidecar file as the metadata is stored directly in the DNG.

This has significant implications for backing up files. If you make a change to a photo which is a RAW file in Lightroom, the change information is stored in the XMP, not the original file. The XMP file is smaller and will update faster. If you make a change to a photo which is a DNG file in Lightroom, the change information is stored in the DNG, which means the entire file is marked as changed.

If you back up your photos (and you should), this means a much larger contribution to your backup bandwidth. If you back up to a cloud or network server, it means a much larger contribution to the amount of network throughput you use, which means time.