This port sounds fine, however, it's horribly unoptimized. The writing style of the .txt makes me think this was generated with SPC2MML. On a quick sweep through the .txt, I managed to lower the insert size down to 0x4F2 bytes, after which I stopped. The $FA $02 $XX command is your friend here; a lot of the patterns which repeat the same note(s) but at higher semitones can just use that command to adjust the semitone tuning of the channel to save lots of space, just make sure to use $FA $02 $00 to adjust the tuning back. For example, the section on channel #2 where a bunch of notes repeat could be changed to this to save lots of space:
As well, I notice that you use a lot of tiny rests after most notes. This makes the .txt incredibly difficult to read and also potentially wastes some space. If you want to make your notes staccato, a more efficient and legible way is to use the q command. In qXY, the X is a value between 0 and 7, where lower values make the notes more staccato. Something like q4f could emulate the staccato better than tons of tiny rests.