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.