Q: What does this do if I'm not max level?
A: It sets your AAXP rate to 0% to focus on getting you max level.
Q: What does this do if I'm max level and have max banked AAs?
A: It sets your AAXP rate to 0% to max out your buffer XP.
Q: What does this do if I'm max level but don't have max banked AAs?
A: It sets your AAXP rate to match your real XP percent. So if you are 25% into your max level, it will set your AAXP rate to 25%; if you're 60% into your level, it will set your AAXP rate to 60%. This was the closer you are to full buffer XP, the more XP you divert to AAXP.
Q: Why does it round up when working on AAXP?
A: Using /alt on 0
sets your AAXP rate to 100%, which is the opposite of what we want when you're max level but have less than 1% real XP, so this solves that problem.
Q: What? Is that it? There is nothing more to this script?
A: Na, this is very basic. I needed something simple to start with.