Shame this doesn't include the secret little "yeah!" that comes in at 20 seconds like in the original, which is fair given how the only time you'd be able to stick around and listen to it without the use of glitches is in Launch Base Zone Act 2. Terrific port aside from that!
A few pointers:
-Triplets work by using note12 and note24 instead of note16^32 and note32.
-You should place $F4$03 before the slash mark, not after. This way the echo doesn't get toggled on and off when looping.
-Having $F4$02 can make smoother note transitions, i.e. make them less choppy.
-You don't need $F2$XX$YY$ZZ for the echo, because $F2 only is used for echo fades and stuff.
-That [r1]99 is unnecessary as you already have the channels filled up.