Tip: If you make a change to your ROM that you regret, just go to File > Restore > Restore ROM to Previous State in the menu. From there, you can select a restore point and revert your ROM to a previous state.
A few quick notes. I swapped #optimized to #default since it inserted fine, make sure to always check that. Also, you could loop some of those big bunches of single notes on channel #4 to save a handful of bytes, and also maybe lower the global volume a bit.