So, a while back mob culling was introduced as a way to remove/reduce server lag.
It was done because at the time people such as myself were stacking hundreds of villagers on a single block to make ridiculously fast spawning iron golem farms and having 100-1000 entities stacked on a block caused some extreme memory leakage.
However since then the spawning mechanics for golems have changed, so doing this has absolutely no effect on the spawn rates and really isn't a viable thing to do, so it seems the extreme culling has out lived it's usefulness.
On the other hand though there's things like cows and sheep which are viable to breed in a fairly wide area, to acquire large amounts of leather and wool, where they wouldn't be getting stacked on a single block causing lag, but still end up getting culled by the plugin when they walk to close together like their AI all to often likes to make them do.
Now there's certainly still some potential issues from things like egg farms where people may stack far too many chickens or idiots breeding 500 cows in a 4x4 space so removing the culling entirely probably isn't a good idea.
But I think at this point it's worth considering an increase in the amount of mobs allowed in a fairly small space to promote people gathering their own resources without having to worry about their animal setups disintegrating because the AI decided to huddle up.
here's a link to the post by cschurz describing the functionality:
http://www.opticraft.net/index.php/topic,12512.msg115877.html#msg115877at the time 6 mobs made sense because as nick so eloquently put it:
This plugin was made by opti with 2 things in mind, stop those ridiculous chicken farms, and to stop those ridiculous villager farms. Throttling mob spawners was just a bonus.
However given the outdated villager technique and the fact that egg farms are so compact they'd still get throttled anyway I think it's worth considering an increase from 6 mobs per 4x4 area. Personally I'd like to see it increased to 15-20 mobs which really isn't to much, and just to prevent them getting culled when I hold out wheat and they crunch together before separating, but even an increase to 10-15 mobs would make farming wool/leather a much more enjoyable experience.
Given the new circumstances it would be rather helpful to see this considered, even if only for a trial run. If memory usage spikes as a result by all means turn it back down. But at the moment I'm reluctant to start certain projects with the current difficulty of acquiring materials, so I'd appreciate your consideration on this matter, thanks.