Got a issue with Primordial Cave spawning to many mobs when I change the chunkGenSpawnModifier in Citadel.
At 3 times the caves lag the game so much that everything stops generating before the caves become visible and at 2 times the mobs are lagging themself. I found 3 times quite nice for the rest of the world however as it seems much more alive.

thats.. what happens when you do that

How about you try recreating the issue and tell me again if that is supposed to happen

chunkGenSpawnModifier multiplies the amount of entities spawned via chunk generation. The default modifier is 1,0

Primordial caves acts like the overworld surface, where chunk generation also spawns animals, thus setting "chunkGenSpawnModifier" to a different number multiplies animals by that rate.

This is behavior which is to be expected if you alter this setting in citadel.

No shit and how many mobs spawn in a single chunk within the Primordial Caves on average? Compared to the overworld that is

Entity spawn in a single chunk
2-5 Grottoceratops
2-3 Subterranodons
1-6 Vallumraptors
1 Tremorsaurus
1 Relicheirus

Combine this with the high tps usage for every animal, and condensed space causes the low tps when loading into chunks with these changes in place.

Just reduce it man.
If you are that sure this is a different mod, do you have twigs or etcetera?

I currently trying to figure out how to post pictures

However I did try normal settings and it still lags as there are simply to many mobs spawning and besides the overworld is basically empty and that is the exact reason this setting exists so you can boost the amount

I got this issue too,but with respawning animals mod instead of messing with citadel