For a moment I thought I might have forgotten that option, convert paths. I tried it again.
The library imports oke, I went to Tools, Rename, find replace to change M: into \data\music. This worked fine.
It looked oke, until I fixed auto import (remove invalid paths, added correct ones) and it ran an import.
Some files got removed from /data/music/.... and MC added them as \data\music\.....
In-depth details:
Imported:
\data\music\Alanis Morissette\...
When I remove the files and re-import them (or run auto-import), they simply re-appear as \data\music.
Many, if not all these albums (directories) have a cue file, mostly because they are single-file albums (flac, dsd), but I found one that simply has files for each track. There's a cue in there too though, so I'll test a re-import of that album after removing the cue file.
I tried the rename/move tool, but that actually shows the files with the correct path.
Edit: so I tried importing without the cue present, it just comes back as \data\music\ ....