Some ECUs can be altered to various needs for different setups ie re-programming them, so the ignition curve can be changed to match other mods to the engine, if u have brought the ecu second hand it may of been re-programmed.

The MFI ECUs on rs turbos arent really ECUs as used on cossies and EFI engines, they are just a way of setting boost limits and the retarding of the ignition for the boost pretty basic really hence why people ditch the MFI setup for better management.

Dont think the rs turbo ECU have the technology in it to put more fuel into the engine, it has to set on the metering unit and a CO Machine so running the boost you said on a standard fuel percentage will result in pinking and blowing your engine up.

As with fitting any chip, take it to a tuner for a setup.