Scott Aaronson's quote in the article provides this constraint:
> Precisely because the Turing machine model is so ancient and fixed, whatever emergent behavior we find in the Busy Beaver game, there can be no suspicion that we “cheated” by changing the model until we got the results we wanted.
Your "each number x is interpreted as n+x" is a clear example of the cheating that makes for an uninteresting scheme.