RF Tools Version: 1.12-7.71

I have an RFTools spawner that constantly spawns witches, but the witches instantly despawn before my automated killing system can kill them. They only don't despawn if I am nearby, or if nobody is in the same dimension as the spawner (it's in a compact machine). It would be nice if mobs spawned via an RFTools spawner had a minimum delay before they get despawned.