I had hoped someone with Mac experience would respond, and maybe they will.
Are you sure the metadata you are concerned with is actually part of the file?
For example, I don't have Mac, but I have plenty of files on my Unraid which contains metadata.
My photos have EXIF data put there by the camera, which contains information about the exposure and other things.
And I have a lot of music in various formats which also contain metadata. MP3s, for example, usually have information about the song title, artist, album and other things stored in MP3 "tags" which are part of the file.
I have no problem at all transferring all of these files to / from Unraid with their metadata intact.
I also have a plex server installed on my Unraid, and it has movie files in its library which have metadata. But that metadata is not part of the files, rather it is stored in the plex database.
What application is in your screenshots?