I think the problem you're facing has more to do with how zombies migrate, instead of how zombies "respawn". Before the 32 update, zombies were only ever "Moving around" in an area that you are in. This whole loaded "square" that you see around you was the ONLY place where zombies were mobile. Anywhere else on the map, zombies were non-existent, and were just saved up as a bunch of randomized numbers, "spawning" into the area as soon as you visited the cell without following a specific pattern.
That's why before, in builds 31 and earlier, you could just clear the square your house is located on, sit inside and never have to face another zombie bothering you again, even after gunshots and helicopters.
Now, after the update 32, the zombies FINALLY got themselves physically saved positions OUTSIDE of the player area, and to add to that, those zombies, outside of player area, even MOVE AROUND when you hear gunshots or helicopters. The zombie movement isn't confined to just a small 50x50 square around your player anymore, they move around the whole city, instead of around you.
Now, to your actual problem, when the zombie hordes happen to swarm a specific place after you hear a gunshot, there is often a huge influx of zombies in a few specific cells close to gunshots, while a huge lack of zombies in cells around them (Because nearly all zombies walked away after gunshot, makes sense right?). The game is handled to see when the cell is "overloaded" with zombies, and when the cell is "empty", and if those cells are located close to each other, then every set amount of time, a random amount of zombies from "overloaded" cell will migrate to "empty" cell to occupy it. It happens irregardless of your "zombies respawn" time, because they are literally "moving in" from another area, not "spawning in".
Okay, so the main question that a lot of you probably have by now : How does a player make a distinction between "Respawning" and "Migrating" Zombies?
It's easier than you might think: 1) If you see a group of zombies (about 5-10, sometimes more) all moving in a specific direction without any kind of meta-event (gunshots, helicopters), then those zombies are "migrating" from other cells.
2) If you are absent from your base in a long loot run, let's say a trip to west point, and after coming back in 4+ in game days you see a lot of zombies in an area around your base, then those zombies are "respawning".
I also dont like survival zombie settings, thats why I play sandbox. try this: Starting population 0,5 peak population 2 peak time ~90 days respawn 10% after 3 days same with migration (3days). With those you can go for loot missions without having to kill a horde whenever you back.
To nerdo 1.Thats kinda a base game issue code wise see to add duck tape pouches he has to change it into a whole new bag and there's no way for it to keep its inventory atm sadly 2.This is a base game issue/decision not part of hydrocraft lol
