I've got two IT-S cars which each started with 165 (plus or minus 2) crank HP. One had a cast iron manifold and an ECU running the fuel and ignition. The other had factory supplied headers, distributor and mechanical fuel injection. I bumped both the half point in compression when I did my IT builds. On the one car, I replaced the cast iron manifold with headers, played with the ignition and fuel mapping (got 12.8 across the rev range with WBO2 readings) and got GOBS more power. With the other, I recontoured the fuel mapping cam in the injection pump to achieve 12.8 across the rev range, found that more advance didn't help much and got minimal additional power.
My issue with the process is the magic number 25%. Many cars can achieve that within the rules and a few will never be able to improve that much. All based on what you start with from the factory.
Chuck