I think playlists should be treated just like as any other list of MC data because they are just another means of organizing files, like Keywords or any other MC field.
I tried a little experiment, and maybe the fog has lifted a little...
As suggested in the topic recommended by pwantzel, I made an M3U
Playlist file consisting of a simple list of file pathnames. It imported as a
Playlist—found under Playlists/Imported Playlists. Selecting the list displays all the files in the list—i.e., they have been added to the library. The name of the playlist appears in "Playlists" in the tag viewer.
I then exported the same files as an MPL playlist, changed some of the tagging information, and renamed the file. When this file was re-imported, it updated the tags, but did not produce an entry in Playlists/Imported Playlists.
So, while both called "playlists," M3U and MPL files are distinctly different. M3U are simple text files listing file pathnames. Importing them creates a playlist. MPL files are XML files for importing meta data to files (which, I assume, will be added if they don't exist). They do not result in a playlist being created.
There is no playlist "field"—it just appears that way in the tag viewer. Playlist names cannot be imported to it, as I previously suggested. It would seem the only way to import playlists is via M3U files. Still, you should be able to import the information to a custom list field (e.g., "Galleries"). The data in this field may be nested by separating levels with a "\". If you do that, you can very easily select any particular gallery for viewing using a pane view. I find this much more effective than using playlists.
Maybe your angel can use Access to create a new field that records the existing gallery relations in the form
level1\level2\galleryx.