The big picture looks like this, where 1=templated class has been instantiated and is managing X registered instances: [ModelDef::ID] [ServiceType] 0 1 2 3 4 5 ... N FixedRollback 1 0 1 1 1 0 FixedExtrapolated 0 1 0 0 1 0 ... IndependentFinalize 0 0 0 0 0 1