I'm going to start working on an observer that gets notification of children and children's children etc. Probably going to call it DeepOffspringObserver unless a better name comes up.
Turns out this wouldn't be very difficult to do, all it is is a Forked Observer that adds itself to its children on updateForkedOffspring. To attach that observer to all the tasks of a process use a frysk.proc.ProcBlockObserver (soon to be frysk.util.ProcBlockAction)