I again cannot stress enough, for the cost of a SAFC you could install an Evo ECU,knock sensor, get the cable and never worry about things like this ever again. But yeah, the SAFC would work.
I honestly cannot understand however why anyone would do anything other than install a fully tunable, damn near bolt in, map switching, NLTS, launch control, SD running, alternate map, valet mode, able to handle 800+hp, big map ECU, for the same price as a box that interrupts and changes just the fuel signal. The only possible reason I can see is someone saying "I can't solder." in which case I say "Learn."
my .02
/brox