Multiple album artists?

[dvdr]

Using mp3tag, I use \\ to create multiple entries for artists, genres, composers etc.
That perfectly works with Minimserver - with currently one exception I could identify: using it on „album artist“ (I actually use both „album artist“ and „albumartist“ as tags), does exclude all the entered artists from the album artist list. Files are mostly flac and dsf, some alac and mp3.
The concept of having multiple album artists may seem strange, but I have quite many classical albums, where for example two pianists play two concertos, two orchestras play two symphonies or I view the conductors as album artists etc.
I don‘t want to split the album in two parts, that’s why I tag multiple album artists.
Is there a way to make multiple album artists work - or a I making a mistake during tagging I‘m not aware of?