Quick note here that is also going to be enforced for all ports from this point on, but do not use $EE on SFX channels. When sound effects play, the change in pitch from $EE is carried over and will result in sound effects sounding sharp. The higher the $EE value, the more off-key sound effects will be (logically). You should define a new instrument in the #instruments table instead.
I fixed it for this port, but future ports (and this is applicable to everyone) that mess up sound effects might get rejected.
All that aside, this is a very nice port, so good job!