Cass this is where an "ALL IN ONE" Arranger like the KORG Pa4x would shine for all what your trying to do,...and you would be carrying way less gear to the gig.. wink
...good luck with your music!
The better "All IN ONE" Arranger choice in your situation would probably be better served with the Tyros 5 Organ World. The combination of physical draw-bar sliders and corresponding buttons makes a very useful combination, as pressing both corresponding buttons at the same time reset that draw-bar to the original preset position.
The buttons on your s950 might work the same way for draw-bars and other functions, but the physical sliders are way easier on-the-fly. Upgrading from a Yamaha s950 to a Tyros 5 (or maybe the upcoming Yamaha Genos) would make more sense from a quality and compatibility perspective.
I played Hammond organs and Leslies for years before severely downsizing to a single Tyros 5 and powered speakers for live performances and gigging. The newer upgraded DSPs on the Tyros 5 and Leslie simulators Organ World are really good.
Also add the Real Reverb DSP into the Reverb DSP block in the Mixing Console and all your Organ registrations makes for a high quality organ experience, creating a better ambiance from an organ playing in a room environment with (low reverb time/initial delay/high damp settings) to a cathedral ambiance with an awesome 6 second or more reverb time with corresponding initial delay and high damp settings.
Also the Tyros 5 quality keybed is to die for, especially organ or the more aggressive jazz organ type playing. At home, a Tyros 5 twinset with midi pedals is the best combo I every had for playing organ, never mind including the full arranger capability.
Marcus
DEMO YAMAHA Tyros 5 Peter Baartmans 02https://www.youtube.com/watch?v=NaHA6zALkLc