I think you are confused, or you have confused me, that's for sure


It's not a "boost ecu", it is an Ignition ECU, it has nothing to do with boost. When you chip an RST, the chip is replaced with usually an unlimited boost chip and a different ignition map. This map is fixed. Each chip manufactuer has a slightly different map. It doesn't matter if your boost is 11psi or 31psi this ignition is the same.

The fueling for the boost level is all set on the metering unit. There are 3 points of adjustment, idle, cruise and full throttle.

I'm not 100% sure what you are trying to achieve...