Mixer and Soundfont question

So I downloaded a soundfont recently for a more realistic gong. When I added and saved it to my score from the synthesizer, I was very happy with the result from the gong, but noticed surin playback that it applies itself to all the other instruments. I checked the mixer and saw that it automatically applied the sound font to every instrument. It was a pain to restore them all to their defaults, but I was able to do it. But then when I opened a new score to apply it there, all the instruments in that one had already been assigned the gong sound font. So my problem is that whenever I download, add, and save a soundfont into my score, every instrument in every score I open is assigned that sound font, making me go through 50+ instruments in the mixer to restore them all to their defaults. Is there a way to disable this? I need to know if I can just add a sound font, and every instrument still has its default sound in the mixer so I can assign the sound font to the instruments I want. Thanks for any help!