Limitations of percflow/percflowbelow instantiation modes in AspecJ5

Recently I enjoyed percflow/percflowbelow advanced instantiation modes in aspectj; but later found considerable limitation(from my point of view) - they are thread bound. In this mode Aspect's TTL is limited to flow-of-execution - ok, this is what they had been designed for, but what if that flow-of-exec. initiates another thread underneath and submit execution unit like callable/runnable to it - wouldn't be nice if that submitted unit could be weaved by aspect as well?
Suppose we have code like: 

public void testConcurrentLogic() {
 ExecutorService exec = ...
 Future f = exec.submit(runnable);
 assert...(f.get());
}

The issue is - need an aspect with lifecycle bound to testConcurrentLogic() and with ability to match joint points in runnable.run(). At current, first part is doable with percflow instantiation mode, second one - isn't.