I'd like to mention that a big portion of the insert size can be cut simply by using the qXY command, where the X stands for length and Y for the volume.
Since there are no volume changes here, you don't need to worry about the Y variable (it can always be F), but the X variable is important here, since it can mitigate extra rests.
If you have a lot of notes that go f+12r24 length wise, it may be worth putting a qXY command at the beginning.

I'm gonna use this part in line 30 as an example of how you can optimize using the qXY command:
f+12r24a12r24f+12r24b12r24f+12r24>e12r24<f+12r24
This collective group of notes takes 29 bytes.

In contrast:
q3f f+8a8f+8b8f+8 > e8<f+8
This collective group of notes only takes 9 bytes

Using the qXY command is key to optimization when it comes to extra rests, HOWEVER, due to the nature of the qXY command, it's not really that precise when it comes to note length.