Answer a request to paste ranking code into AI

You work on an ad-ranking model. Its scoring formula and feature weights are a closely kept trade secret.

An engineer wants to paste the real scoring kernel, weights included, into a public AI chat assistant, to get advice on vectorizing a hot C++ loop. Their argument: "It's just math, and the model has seen code like this a million times." Your company has no enterprise agreement with that assistant's vendor.

What do you tell them, and what do you allow instead?