Currently, Polyphone supports muting and soloing individual zones by right-clicking the zone title and selecting either "mute" or "activate solo". It would be really helpful if there was also a solo mode that would automatically solo the currently selected zone. Perhaps this feature could be called "auto-solo". The normal solo mode could be renamed simply "solo", as the word "activate" doesn't really seem necessary. Viena, Swami, and Vienna SoundFont studio all offer a mode like this if you'd like to see how it functions.