What UZO says is true in that it would end up using a lot of channels.
My renditions will do that as well, but they won't use GX-SCC. I can pretend they use VRC6 though to get away with it.
The problem with GX-SCC is that the waveforms it uses are more like MSX and Commodore, than they are NES. NES used better sound altogether (and with VRC6 and 7 it was just superior in every sense of the word). Telling GX-SCC to just use "Famicom Sounds" doesn't help, as all it does is use "Square Wave" for everything.
It's a neat tool but it's not perfect. Too bad, too... since I was hoping the creator would update it. It's still nice to hear, though.