The fact that with transformer stacks you can wind up with state changes being discarded on exception if you get the stack arranged in a particular order isn't what I'd call a _feature_ of transformer stacks :-)
If effect A is invoked before effect B, effect A should happen and stay that way: if I update state before an exception is thrown, the update should persist. If I send a network message before an exception is thrown, the network message is still sent. If I launch the nukes before an exception is thrown, the missiles are still flying.
If I want to batch up state updates to only happen together as a unit, I'll use a transaction effect.
