Prompted by a post on the Reddit group I figured out a technique where you could 'automatically' sample external synths so that you can load them into the Deluge as a multi-sample instrument. I'll just copy and paste the text below. I've got it to a point where you can auto create audio clips for each note but then I don't know what to do with the audio clips (in terms of naming and saving them).
From Reddit post:
_Create a Synth track (just use any preset). Then on the grid put down notes at the start of the pattern that you want to sample and make them the entire length of the clip.
Now go into the Arpeggio (ARP) settings and set: Mode = UP, Octaves = 1, Sync = 1 bar
Press play on the Deluge and you should hear each note played individual each time the clip loops.
Go to Song mode.
Add an Audio track and set the input to 'OUTPUT' (this is just to resample the Deluge output, you'd set it different for external input)
Hold down RECORD and change the mode of the audio track (press the MUTE/LAUNCH pad) to flashing red.
Press PLAY and then just as the last note in your arpeggio chord is playing, hold down RECORD and press the AUDITION pad on the track BELOW the audio track.
The Deluge will record individual audio tracks for each note.
Press the MUTE pad on the last audio track to stop recording.
Now, at this point, we have several audio clips containing a single note but I don't know (yet) how to save those so that you could the load them as a multi-sample set._