Well I have to say, I've lurked about the forum for a while before now, and it seems you stumble upon quite a few ingenious little tricks jaynabonne.
I haven't tested your suggestion yet, but it sounds rather like what I was hoping for.
I'll try to remember to post my results after some testing.
Thanks for the help.
tangent:
the fact that the earth is hurtling circuitously through space whilst spinning is one of the major reasons I don't want to use cardinal direction terminology.
As for not using any predefined ordinals, that's mostly due to the fact that every structure is pretty arbitrarily aligned.
Most of the maps will be drawn in the way that they fit on the screen best, rather than according to their orientation. an exceedingly long vertical hallway won't fit on the screen like a horizontal one, but the vertical axis is presumed to be North-South.
The name of the direction something is in, is less important to the game than the object/path/room it leads to.
Its a difficult point to put into words, as I'm finding, which is one of the reasons I abstained from attempting before.
(Its like reading a language you can't speak aloud. You know what it is, but not how to say it.)
EDIT: Ok, so using jaynabonne's suggestion, I discovered (at least in quest 5.5) that the only requirements for making the compass work are:
<listalias>north</listalias>
<alt type="stringlist">
<value>n</value>
<value>north</value>
</alt>
I'm not sure why the listextend name is different from suggested, but adding these two properties to all my exits (with the appropriate direction) makes them work from the compass correctly.
I'm quite pleased that there was a simple solution, and I thank everyone for their assistance.