I'm trying to use the InControl mod to spawn in mobs, in an ambient sort of way, by restricting them to certain biomes at given densities per chunk. This is presenting a few issues.

1. The mobs can't be set to despawn by InControl as any kind of override. It would be excellent to be able to toggle something which would either persist or force despawn entities which InControl had spawned in when you unload chunks (or - of course - use the mob's default despawn rules).

2. When you reach a new chunk and finally the mob-density is below the required level, suddenly a tonne of mobs spawn all at once until their density is back up to the per-chunk limit. They all tend to spawn at the same sort of place relative to the player (though yes that can be adjusted via config to limited extent), and you get a big density in that chunk, leading to mob-lag. This is the same when you start a new world: the starting location chunks are chock-full of mobs at the max density, and then when you go wandering there are no mobs anywhere until you have enough chunks explored for another massive "burst" of them. It's particularly when you travel a distance over sea and arrive at a tiny island.... which immediately populates with far far too many mobs for its size!

What this really needs is a metric so that once you reach a threshold for more spawning a "probability of spawn occurring" is used, so that the mobs are far better spread out in the world.

Best wishes!

I've had some luck addressing this by using the random check set to a very, very low value. That way, mobs can't spawn all at once, and even when a lot of new slots become available all at once, it still takes some time to fill them all in.