I can not send the audio region info over the existing network protocol without breaking backwards compatibility. Maybe I will find a way in 3.7 but currently it is not possible.
I guess with the different setups you have you might be better off with using the multitrack features. That way you have only one song and can decide on a gig to gig basis which tracks should run and which should be muted. Just make sure that instruments always use the same tracks. For example Drums always on Track 1. Then in settings you can turn off track 1 for all songs with a single tap.