0.4.2
When using the sink in the Bog house, there is an option to leave a jar under the faucet. Choosing this turns off a light and renders all controls unresponsive.
No, that is not a safe rule of thumb. If there were another clause between "but" and "she prepared it masterfully", one would need a comma. (e.g. "It was quite a simple dish, but, as she'd done many times before, she prepared it masterfully.")
As it stands, however, an additional comma would be incorrect.