Every ZP works like a 4-stager.
It gets complicated about talking about actual 4-stagers, but they work the same way.
Anyways let’s pretend we’re talking about a normal ZP title like New Emperor because it’s the same logic but with easier explanation.
New Emperor ZP has a mini 4-stager inside of it. The “beginning” of the sub is stage 1, the middle of the sub is stage 2-3, and the “end” of the sub is stage 4.
We know from the producers that after about 7ish minutes (each sub is a bit different) that you’ll run through all four stages. So when I say the “beginning” of the sub I mean the 0-second mark and when I say the “end” of the sub I mean the 7 minute mark.
We also know that SaintSovereign said you get the whole thing in about 5 minutes as @SoulFire mentioned. and we know that it’s recommended to start off with 30-60s of a dense title on your first listen, and increase from there.
So if I’d take a guess I’d say Stage 1 could be the first 0-30s or 0-60s, stage 4 could be the 5-7 minute mark, and stage 2/3 are somewhere in between. Again, it’s different depending on every sub, and doesn’t really matter. Why SaintSov probably said you get the full script within 5 minutes is (MAYBE) because you get the full script (stages 1-3) in that first 5 minutes, and then from there, Stage 4 is just a re-hash of the first 3 stages.
Important: Every stage is a complete version of the script in itself. Meaning you get the full script, in ever more and more complex versions, every step of the way. Saint & Fire are always saying you don’t need to worry about getting the full script, not because it’s effective even without the full script, but because the full script is always there, with lighter versions at the earlier marks and more complex versions at the later marks, so all you need to do is find your sweet spot.