Each MB I know takes about eight seconds of pressing the power button to
switch "off". Besides that, having a four-seconds-delay seems rather useless
if you'd switch from "0s -> shutdown, 4 s -> hard shutdown" to "0 s ->
suspend, 4 s -> hard shutdown". I never tried it myself*, but I'd expect
"0 s-> suspend, 4 s -> shutdown, 8 s -> hard shutdown".
If I happen to be correct here, you'd be looking at the wrong side of the
*)I'd fail, because I put in a relais, which would cut the power anyway.