Apple claims the heat issues with the 15 Pro stem from poorly optimized code and will be resolved through OS and third-party app updates. But if the thermal engineering truly is the culprit, then they are dealing with a fundamental hardware flaw.
And if addressing the heat issue is their goal, there is only so much they can do in terms of software optimization. Unless they get very lucky and strike gold in terms of finding and correcting poor code, they will likely need to make performance worse to achieve the desired result.