typographically in the sense that, for some of those examples ('half-baked', 'broad-minded', 'two-tone') I wouldn't object to seeing without the hyphen, but for some ('get-together'), it wouldn't really work
so the distinction between hyphenated and closed compounds is half typographical and half standardisation I guess
that being said, open compounds are often hyphenated as well...
How are you to-night, Helen? Have you coughed much to-day?
Why does Jane Eyre have a hyphen in to-night?
Does it signify that the pronunciation in Emily Brontë’s day was [tunáit], not [tənáit], or what?