Six bytes are saved. One is saved by consolidating setting !MusicNoiseChannels
and $0389 into a Noiz subroutine, but only with !noSFX set to !false. The other
five are saved by recycling VCMD $F8's code.

!noSFX gets a different saving: namely, by getting rid of a redundant set of
!MusicNoiseChannels, because VCMD $F8's code does the job instead, and it's
never skipped since the SFX check naturally does not exist.

By taking advantage of the accumulator and recycling a call to KeyOffVoices
(though we skip clearing !PlayingVoices), we save two bytes.

This one (and a missed optimization) was also ported to the old unpause silent
SFX ASM that was kept for historical reasons and also to act as an example.

This does the same thing as checking for a zero in Y. The accumulator is
overwritten, but we're not really using it afterwards, so we save a byte.

Y is already zero in the first place, so we save a byte by doing this.

… echo RAM

This saves four bytes.

This saves two bytes.

Set these prior to performing the ID comparisons for ProcessAPU1SFX. Saves ten
bytes in the process, but they're only saved for the hardcoded 1DFA SFX.

Another three bytes saved by doing this, but again, only for hardcoded 1DFA SFX.

This does the same thing as checking for a zero in Y. The accumulator is
overwritten, but we're not really using it afterwards, so we save a byte.

Calling L_09CD then jumping to pitch is already handled by the main SFX
code, and jumping there saves three bytes for the hardcoded SFX.