So now the question begs to be asked.  If there are 2 or more tags with the same name, with or without values. How do you remove a specific tag that you want to remove.  If I use the metaflac command:
metaflac --remove-tag=SongRating WorkingMan_Copy.flac
it removes both.

metaflac --no-utf8-convert --export-tags-to=- WorkingMan_Copy.flac | metaflac --remove-all-tags --import-tags-from=- WorkingMan_Copy.flac

metaflac --no-utf8-convert --export-tags-to=- WorkingMan_Copy.flac | grep -v '^SongRating=$' | metaflac --remove-all-tags --import-tags-from=- WorkingMan_Copy.flac

The 1st action (2nd in the tweaked) in the command seems to be exporting the tags to to themselves.  Is that right?
I see the metaflac help says to use ‘-‘ for stdout.  But it also seems to require a space after that, is that correct?

• The first metaflac produces a tag listing that is passed to
• grep which removes (-v) "SongRating=" from the listing and passes the output to
• metaflac which reads the tags from STDIN and writes them to WorkingMan_Copy.flac.

$ metaflac --no-utf8-convert --export-tags-to=test.txt WorkingMan_Copy.flac
$ grep -v '^SongRating=$' test.txt > stripped.txt
$ metaflac --remove-all-tags --import-tags-from=stripped.txt WorkingMan_Copy.flac

• The | ("pipe") sends the output to the next command.
• The next command, findstr (or grep if you have that) is a string finder. /B finds it only at beginning of line, /E finds it only at end of line, so that means you are searching for a line that is "SongRating=" and nothing before or after; /V means to invert it, so to return every line that does NOT match.

• Then piping what grep/findstr found (namely the whole shebang except lines that are exactly "SongRating=") on to the next command. Which is another metaflac, that removes all the tags and imports the tags from "-" which is the standard input it was sent by the command before the pipe.