I decided to have a go myself. I set up the IAC Driver and enabled it as an Input Port in Live. I loaded the preset in Live's first MIDI track and set the MIDI From to IAC Driver. I then switched to Bitwig and on my first track, set the MIDI Out to IAC Driver 1. Amazingly, it works! I haven't managed to sort out being able to select different tracks in Live by changing the track being played in Bitwig, nor have I found a way of transferring the audio prduced in Live back to Bitwig, but hopefully these mysteries will be solved in the clear light of a new day, tomorrow ๐ If the worst comes to the worst, I'll just capture the audio as a WAV in Live and copy it into Bitwig.