In reply to French Punctuation (Extra Spacing):
Ryan, the same way the length of spaces can vary a lot between fonts — the space in Cycles eleven is 180/1000, which is ten percent less than a thin space if it is defined as a fifth of an em — so do the absolute and relative lengths of en-dashes and em-dashes:
(click to enlarge) For careful editing, I personally see no other solution than to fix or have fixed the lengths of those dashes to one's needs.