PL4 copies metadata in RAW files through to output files (e.g., JPG) with metadata (as chosen in the Export dialog, without changes. This has been very helpful.
PL5 with its additional metadata capabilities handles things somewhat differently. Because I manage my metadata in a separate DAM (IMatch), I have preferences set to disable metadata synchronization. I’m pleased that this option is available.
However, PL5 changes hierarchical keywords from the RAW file when writing the output (JPG) file. Specifically, for example, ‘animals|bird|eagle|bald eagle’ is rewritten as ‘animals|bird|eagle|bald eagle; animals; bird; eagle’. For someone who manages their metadata in PL5 this may be fine, but it creates unnecessary problems and complications for me because I have a carefully chosen keywords hierarchy for things like bird descriptions. PL5 creates additional ‘top-level’ keywords which I don’t want or need, and greatly increases the total number of (duplicate) keywords in my photo database. - → This is a very undesirable change from how PL4 and prior DxO program handled keywords!
PL5 needs an additional option in Preferences to write keywords from the RAW files exactly as they are (i.e., unchanged) into output files.