He could, but he'd be running ~22% rich. The stock injectors should be close to maxing out at that point, assuming no increase in pressure. I've seen 50ish% duty cycle on my 750's(at a lower pressure, probably closer to 600-650cc) with the stock turbo at 12-14psi(intercooled, full exhaust, etc, probably close to 250rwhp), so that's pretty close to the limit for the stock injectors.
I'm not that well versed in making the stock ecu work at higher power levels, but I believe people make them work reasonably well with rising rate regulators.