Ok maybe no one is answering this because I'm being too general with my question?
So at 2.5a it says this about spacing with dashes:
"Print is often inconsistent in the spacing before and after a dash. In braille, no
space is left between a mid-sentence dash and the words that immediately precede and
follow it, regardless of print spacing."
It then shows an example:
He is tall -- six feet anyway.
and the brailled sentence indeed has no spacing before or after the dash. So far so good...
But then later on page 2-7 it says this regarding spacing and incomplete sentences:
"One space is always left before beginning a new braille sentence. Thus, if a dash
begins an incomplete sentence, or a fragment of a sentence or thought, it is preceded by a
space. And, when a dash falls at the end of an incomplete sentence or thought, it is
followed by a space. Examples:
Oh, my— Jessica wept."
And the brailled sentence above does have a space between the dash and Jessica. Maybe I just don't know what an incomplete sentence is but in the first example "he is tall -- six feet anyway" the second part seems like an incomplete sentence to me so why isn't there space between the dash and "six"?
For that matter...another rule says: (also on 2-7)
"When a dash represents a pause and separates complete sentences, it is recommended
that spaces be left before and after the dash."
Hooray! We won. — Oh, boy! — I am truly happy.
And if I go back to the original first sentence "he is tall -- six feet anyway" one could argue that there is a pause there...and if so...there should be some spacing after the dash.