> All it takes is a modulator that controls whether to let the LLM text through the proverbial mouth or not.

> (Of course, finding the right time/occasion to modulate it is the real challenge).

This is tantamount to saying:

  All you have to do to solve a NP-hard[0] problem is to
  make a polynomial solution.

  (Of course, proving P = NP is the real challenge).

0 - https://en.wikipedia.org/wiki/NP-hardness

Your analogy would be better if it were the construction of a heuristic.

GP seems to have a legitimate point though. The absence of a workable solution at present does not imply the impossibility of such existing in the not so distant future.