Change MIDI Sound mid-way through piece

Hi

I am creating a choral work with an organ accompaniment. I have included the Jeux organ soundfont, which is great. However, I want to be able to change the sounds in the mixer mid-way through the piece. A simple example: starts off quiet, gets louder, finishes quieter with the same sounds as at the start. I can see that you can use the 'Change Instrument' text and that works - sort of. It is clunky. In order to go back to the original sound, I have to change instrument again as I don't seem to be able to select a previous instrument.

Likewise, I understand it is possible to use a Mid-staff Sound change, but in order to use that, I would need to change the organ part to a violin/cello.

Ideally, I would like to find out it is possible to simply change the sound in the Mixer mid-way through a piece without having to create multiple staffs for the same instrument in order to setup different sounds throughout the piece? Possible?

Thanks