where to store my own application attributes?

Where do people store their own application-level attributes?
#myDbLocation, for example?  This is such a basic question for every
web app, I'm surprised tto find he answer so elusive..

I was looking at WAApplication>>#preferenceAt: and #preferenceAt:put:.
Even though DB Location is a property, not "preference" I thought it
would at least work..

Nope.  #preferenceAt: goes through its WAUserConfiguration's specific
set of "attributes", which I have not yet figured out how to extend..

.. and I'm not sure I would want to because access to those attributes
is very inefficient -- creating a temporary IdentityDictionary and
IdentitySet, enumerating all "ancestors" and each ancestor enumerating
its "localAttributes" while adding and checking the IdentitySet in an
inefficient way too..

Maybe I don't need efficient access, not sure yet, but I was really
just looking for a properties Dictionary I could use; simple, fast and
unrestricted...  That's what I thought the #preferenceAt: was.

Now I see besides #attributeAt:, WAConfiguration also has #at:,....
but its not obvious what it is doing.

Do I need to define my own subclass of WAConfiguration to do this?
Any advice is appreciated..