I don't think so... Since the WRX is a 3BAR, and the stock RS one is 1BAR, the ECU would never see a high enough pressure. The stock would output ~4.98V at 14.7PSIa, whereas the WRX one would put out ~1.7V. The ECU would assume it was at a lower pressure than it really was (and therefore not put in enough fuel or timing).
It MIGHT work if you had bigger injectors, but you'd have no way to tune it.