Having spent a day of experimentation yesterday with the MIDI Environment in Logic and the Audio/MIDI setup app, I think I can safely say – they are not clear. Yes, that’s the polite way.
So my current approach whilst I continue to experiment is http://www.subtlesoft.square7.net/MidiPipe.html – an awesome little app which appears to do everything I need for the moment.
Would still like to try and handle this completely within Logic though.