CachedSource/Source clone="true" Never Set in rasterproxies

I am using rasterproxy mode with MRF files on S3 that have matching compression to the settings listed in the config.xml for OR. Based on the guidance in the MUG https://github.com/nasa-gibs/mrf/blob/master/doc/MUG.md#cloning-mrf, this should result in a clone MRF with , however OR does not add the clone="true". Reviewing the OR code, there is only one spot where this attribute is ever set, and it seems to be for the now-deprecated clonemrf mode (https://github.com/Esri/OptimizeRasters/blob/ca5661bc0993ae96548b618cbfedb58217c29d8c/OptimizeRasters.py#L1634).

Maybe there's more to it that I'm not aware of, but this seems like an oversight.