Tip: Layer 3 backgrounds and tides disappear when you hit a message box, so plan your level around that. For example, you can add a sublevel without layer 3 at the start/midpoint, and include your message there.
First, you don't need v0 at the beginning of #6 since all that's playing there is rests; this just takes up extra space.
Second, you don't need to keep redefining @10 for every note (unlike with instruments @[email protected]) since it is not considered a percussion instrument by AMK. Hence, redefining it for each repeated @10 note takes extra space.
Third, I changed #optimized to #default since it inserts fine.
Finally, since channel #5 was completely empty for the version without Yoshi drums, I changed channel #6 to channel #5 to prevent any SFX cutoff.