Really just a protection for external users accidentally incurring a perf cost if they try to manually generate edges. We will never do this more than once per particle per cluster union.
Chaos/ClusterUnionManager.h
bIsAuxiliaryParticle
uint8
An auxiliary particle will be removed from the cluster union if FRigidClustering::HandleConnectivityOnReleaseClusterParticle detects an island made up of only auxiliary particles.
