My hunch is with Logic 2 you brought the answer. The general rule of self-test could still apply it seems, only achieved through a more complex logic and not just a timer.
Funny story: I once flew for an operator whose CAA thought the tank segregation for take-off was of high importance. Hence we had an SOP to time after engine start for 2 minutes, in order to observe the limitation and avoid departing with them running.