Is there a way to automate the currently selected sample in Live?
Even among a set of preselected sample choices?
Currently un-possible. I'm adding a feature request for this.
However, a workaround would be to make two or more patches equal in everything but the sample source, and use MIDI program select or something to switch between them. The sound engine is not required to do a reset between patches, and so if the body types etc. are not changed, you should have continuity of sound.
If you find the MIDI Programs are not being sorted correctly, that's not you, it's a recently discovered issue on my end.
Hrmm… I think I see what you are getting at. I guess I'll need to read the manual again to be sure. I guess I can't test it in the demo version though as I wouldn't be able to save a variant patch.
The patches are just JSON files. You should be able to edit the sample_name parameter and save a copy with a text editor. Then you can switch between those patches either with the main patch menu or by putting them in the MIDI Programs directory and using pgm change.