I’ve setup song groups so that I can control the mix to headphones/monitors and main speakers as separate mixes for each song and for each instrument and audio/MIDI tracks. I assign the piano to PHeadMix and PSpeakMix, I then save the project, go to a different song and then back to the song I saved the outputs on and VST Live haschanged the output of the piano to the name of the song. The piano is still going to the PHeadMix, but at a lower volume.
This is my saved settings:
After song change and back to original song.