Good point. The numeric panels names are replaced by the textual names when an import happens. It seemed friendlier. However, if you're importing you don't know what the name of the panel is until after it's imported.

Well, it doesn't look like Roon is seeing those extra tags. I'm wondering if there's anything I could do differently?

Does it need a full date, because sometimes only years or years & months are available?

The tags appear to be mapped correctly for FLAC (although it does make me wonder what will happen when I come to edit the tags of my AIFF files). It says it's disabled due to open files, but I assume that only refers to changing the mapping.

When I add the information in manually, it appears as part of the main string under the album title:

Flac/Ogg mappings were disabled as it would be very bad if the mapping were changed while the files were open.

I did read somewhere in the Roon forums that the manual vs. import presents things differently. 🙁