Changing Instruments

So I recently downloaded the Saint James Soundfont collection and there are two different soundfonts for detache and arco. Now I want to be able to use both on the same staff, but in the mixer there are only 3 channels and there are five soundfonts I'd wanna use (namely the tremolo, detache, arco, pizzicato, and solo soundfonts). I experimented and found that by changing the instrument into another violin, I could theoretically add three more channels, but I found that I couldn't go back to the previous 3 channels since I hadn't discovered a way to return to the previous ones since the Change Instruments system text only adds another 3 channels. Is there a way to cleanly do this without adding more and more channels in the mixer?