There were some recent posts (either here or reddit) supporting the claim that different regions activate when reading programs vs when reading text. If we take that to be true; and squint just enough, one could claim that arithmetic and mathematics should be treated differently to language.

I would only find that satisfying (from a snobbish and impractical perspective) if we were able to have the model decide: 1) what encoding should this section use? 2) how should I train this encoding?

A mixture of experts but for encodings is interesting, though!

Maybe there's a clean way to implement

For arbitrary documents and queries, how do we reliably segment the text between those two different languages? And if we can do that, why can't the model do it implicitly?