w/o ever using a regular window
Well, you could hack that "certain file" (not that I know which offhand) that FF uses.
Imagine that would work.
Find that file, open those sites on a different computer, copy that file back onto yours.
Problem is, whatever file it might happen to be, may very well contain more then "just" zoom settings.
And I take it you're adverse to opening that regular window, once, setting zoom, then clearing out its history?
(And not that I'm really sure just how to go about that either?)
Fire 750, bring back 250.
Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:188.8.131.52) Gecko/20110420 SeaMonkey/2.0.14 Pinball CopyURL+ FetchTextURL FlashGot NoScript