Help with Location directive -- will this work?

Hi, I am running a subversion webdav site on a debian machine (sarge)
running Apache 2.0.54. It is all working well but we are trying to
impose access control (much like with ".htacess" files) by using
<Location> directives, since I can't use <Directory> and/or .htacess
files with a subversion repository.

I have had only limited success attempting to control access. Also, I
am using htpasswd and local files so i don't have to deal with PAM (at
least for now).

Essentially, I have these groups:
developers
admins
consultants
"superuser"

I want the superuser to have complete control. I want admins to be
able to create/delete in most directories with in the repository,
developers can create/delete only in the "trunk" and "snapshots"
directory and consultants might be restricted to specific locations
within the repository.

I have been using <LimitExecpt> to implement these controls. Nothing
is working very well. At most I can control the root of the
repository, by restricting write/delete access, but otherwise I don't
get the "fine grain granularity" I'm looking for. Can this even be
done with Apache 2.0.54 and <Location>?

Here is a typical structure I an trying to get working:
https://isl -- only the superuser can add/delete/change
this directory
https://isl/released -- only the admins can add/delete/change
this directory
https://isl/released/.* -- only the admins can add/delete/change
from here on down

## <root>: only superuser can change, everyone can read
<Location /isl>
Order allow,deny
Allow from all
DAV svn
SVNPath /var/lib/svn/isl
AuthType Basic
AuthName "Isl Repository"
AuthUserFile /etc/apache2/userfiles/superuser.txt
<LimitExcept GET PROPFIND OPTIONS REPORT>
Require valid-user
</LimitExcept>
</Location>
## <root>: everyone can read, only admins can write/delete, etc.
<Location /isl/released>
Order allow,deny
Allow from all
DAV svn
SVNPath /var/lib/svn/isl
AuthType Basic
AuthName "Isl Released Subdirectory"
AuthUserFile /etc/apache2/userfiles/admin.txt
<LimitExcept GET PROPFIND OPTIONS REPORT>
Require valid-user
</LimitExcept>
</Location>