Solo the external instrument track and go File>Bounce>Project or Section (or press command+b), select 'Realtime' and 'Add to Project' and bounce. Open the project audio browser and drag the bounce to the desired track ?
Thanks for your response. While this definitely works (and is what I use for midi-only outboard-gear-only recording when I need to create a wavefile of the full song, with processing.. This kind of "print the efx + processing + volume settings" wavefile is not necessarily ready to be "put back in". I'm hoping to record the synths dry, with the External Instrument - which does not seem to be supported with Logic Pro X.
So the solution is to create an Audio Track, set it to the input, arm it, press record and record the results into a wavefile, then move the effect chain + routing from the External Instrument track to the new Audio Track. That's fine. I was just expecting there to be a faster cooler better way, which would have enabled me to "convert" an External Instrument track into an Audio Track, (and, before that, duplicate the External Instrument track and use that for the next parts) without fiddling.
I can easily modify my external midi gear Logic template so that it already has a couple of audio tracks ready and wired for receiving audio. It's no hassle.
I just wasn't sure if that was the only
way to do it in LPX
Thanks for all the responses!