Help with learning to break out of neutral

Hey there guys and gals. So as of late I've been focusing a great deal upon how I play in neutral both as Zss and in the game in general. While it has helped my play immensely and in general has allowed me to play more consistently, I've come to the conclusion (after reviewing my matches and talking with local players) that while my play has become much safer, it's almost entirely because I've learned how not to over extend, not when it's safe to push out. Granted I know how to kill, and do it with style, but I feel like when I'm in neutral the options I throw out are done solely with the objective of covering an approach or limiting how they can come at me, but with no thought of how I should follow up on them or out what that move will setup for. So more often than not, when I get the hit I'll either briefly extend and attempt to further the combo or else immediately retreat just outside of their range and go for a second single hit; kills only come when the hit happens to create that one familiar setup that I've rehearsed and practiced endlessly.

As of right now my plan is to literally make a playbook for myself. I'm starting by creating 3 general goals: killing off the top, the sides, or the bottom blast zone. For each goal I list the option that accomplishes this directly, along with scenarios/positions where they can accomplish these goals and the percentages at which they accomplish them. From there, I'm trying to sort of reverse engineer ways of setting up these options by figuring out what options will put them at the required damage, and desired position, and from where they need to come. For example, off stage, b-air kills most characters off the side blast zone around 85 percent. If I simply throw them off stage and go for the b-air they may air dodge it, which means I lose stage control and potentially my stock, so it's not a great setup. If I knock them off stage around 80% and go for a ledge trump however, it gives me a free setup, and almost perfectly guarantees the kill. From there it becomes a question of what options should I be going for on stage in neutral to set up for this, or for that matter what strings may inadvertently setup for this and at what percents.

So my question is this, what are good ways to go about working on this aspect of my play? Does the method that I've outlined above sound like an effective one, or are there things that I should be changing?