Disable unix-domain sockets?

I'd like to avoid having to specify the unix socket directory when
starting local instances of postgres, due to the new restrictions on the
characters that can be in its path
http://archives.postgresql.org/pgsql-bugs/2012-09/msg00012.php
(only partly solved by a recent commit):

This needs to be specified with the -k command line parameter:
http://www.postgresql.org/docs/9.2/static/app-postgres.html
or the unix_socket_directory configuration setting:
http://www.postgresql.org/docs/9.2/static/runtime-config-connection.html#GUC-UNIX-SOCKET-DIRECTORY
where it is documented as being for unix-domain socket connections.

I hoped that if I didn't use "local" in my pg_hba.conf file, instead
using just "host", then postgresql might not allow unix socket
connections at all, so it wouldn't need to create that .lock file.
http://www.postgresql.org/docs/9.2/static/auth-pg-hba-conf.html

But postgres still tries to create the .lock file, failing here on
Fedora because it defaults not to /tmp but to /var/run/postgresql, which
the local user can't write to.

So is there some way to avoid the need for the .lock file, or should the
documentation say that the directory is needed regardless of the
connections allowed?

And if not, is there any downside to just using /tmp ?

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