I couldn't get the df to work - my dd went through a very light sleep phase between 10 and 11. If I gave her a df she'd wake, fall back asleep at the breast and still wake at 1ish, so I took to only feeding her if she'd woken herself.
I figured it better to let her sleep for as long a patch as she could, knowing that in the second half of the night she'd wake much more often anyway.