pg_dump -F f

I notice in the pg_dump code that there is a demonstration version of
dumping to multiple files ("-F f"). Is this a work in progress or was it
abandoned for a good reason - and could it be used in a production
environment? I ask because it would be really useful to me because I
could do a differential backup of the dumped files.

Thanks

Howard Cole
http://www.selestial.com