I hate metric ...
But when I have to deal with it, the zoom factor is usually my biggest 'hump' to overcome.
In Paper space, I'd make sure the border is in metric.
The best way to make sure is to take an ENGLISH border of the same size and overlay the 2 borders.
(English E Size to Metric E Size)
The english border should be smaller by "two thirds" (give or take a few units.)
The reason why is the base units.
In english 1 means one inch.
In metric 1 means on millimeter or whatever you've deamed for that one unit to be.
Once the border has been established.
You're only hump is to figure out the "Zoom Factor".
Then plot 1=1 (don't forget to check the metric box for plotting)
This process shouldn't differ from what you do in English units. Right???
Hope that helps.
Rich
PS
I usually draw a line in meter length in model space.
Then I measure it in paper space in INCHES!
First,
I figure out what the METER line should measure in paper IN INCHES.
Then,
I divide what I want by what I got ... to get my zoom factor.
And this usually works!
Good Luck