the worms/centipedes that are on tenebris are based on the segmentedUnit prototype, the worms on vulcan use the same thing, well, turns out segmentedunit isn't super optimzied, at least not to the amount that tenebris uses them, you don't notice this that much on vulcan due to low density of units, but tenebris seems to use much more of them, so the lag really shows , to reduce lag in your current world, you will want to delete chunks, i reccomend getting some kind of chunk delete selection tool mod, and turn on debug setting to view all made chunks (since there are chunks genned but not shown to the player) and then delete far away chunks that you will not use
