I have a Novation SL MKII an don`t use automap (anymore). Roman Sharov did a script for Ableton that works excactly the way I like.
viewtopic.php?f=1&t=192290
It doesn`t work with Nocturn, but you`re not forced to use Automap with Ableton.
You can either midimap your knobs and "faders on the fly" in Ableton after choosing the controller script for the Nocturn that comes with Ableton (Options->Preferences->MIDI/Sync->Control Surface->Nocturn), or just use the standard settings of this script, or write your own controller scripts.