Zee v. Zed

This has been bugging me for a while.  In SGA, everyone makes sure to put 'Zed' for ZPM when McKay talks, which is fine since it's canon.  But what about Beckett?  The only reason some Canadians say 'Zed' when Americans say 'Zee' is because the British pronounce the letter that way.  So it would make much more sense even than Rodney saying 'Zed' for Carson to say it that way.  Which makes me wonder why no-one does that in fic, let alone why it apparently never made it into the show.

The other thing that bothers me is people who are not Mark Twain writing characters dialectically through the whole story.  Just grates on my last nerve.