If you use that 7 seconds to automatically shut off the natural gas, how do you turn it back on? Once NG is shut off, pilot lights go out and turning it back on means you have a whole lot of homes with natural gas flowing and a pilot light that's not lit. IIRC that's not a good thing.

In my situation, given the likelihood of a high false alarm rate (duh, SOCAL), I'll wait 7 seconds and see what happens.