We acknowledge the source of the confusion.
Here is how we read Sections 4, 5.7 and 6 from the Rules together.
1. Score-based prizes: You may use another participant’s public code as a base, as long as its licence permits it, you credit it clearly, conform to all requirements the said license has and add substantial changes of your own. Reusing the published constants that are part of that method is fine; they are part of what you are crediting. The test is whether your own work, not the reference code, earns the rank or prize. If the result is the public estimator with minor changes, we may rule it out of prize considerations or official leaderboard positions. The Organizers make that call at their sole discretion during the final review before any prizes are awarded.
2. Algorithmic-contribution prize: The same holds. Your write-up should clearly describe the reference method apart from your own and assess your contribution on its own merits. We will judge only the algorithmic contribution / analysis that is yours.
3. Attribution: Keeping the original MIT copyright and permission notice in the source files you ship, together with disclosure in your write-up of what you started from and what you changed, is sufficient. Note that different licenses might have different requirements. Please err on the side of stating clearly which parts are yours and which are the original author’s.