I was going to say... if you're talking midrange cruise
conditions, you should be at 14.7:1, period.
If you have an EGT issue, it's timing related. A WRX in the 2700-3500 range (typical highway cruise) is in the 39-42 degree area. Where the STI is about 3-4 more degrees above that.
In the midrange for spoolability, I'd lean out a touch and add timing. But cruise conditions are what I've stated.