Break generated exec code into subpackages?

Is it possible to break the code generated by the exec section of the config into subpackages?

Motivation: I have a fairly large project and the generated exec code is about 1 million lines of code. Since all this code is in one package, any change, even a tiny one like fixing a typo, requires recompiling the whole package which can take a few minutes, which really slows down development. Breaking the code into subpackages would allow for partial build-caching of the generated package and improve build times in development.

I've found other related issues, for example #1265, that talk about splitting the generated exec code into separate files, but not into separate packages.

Ent does something like this by putting each model in its own package within the ent package so that changes to a single model minimize recompiling (their motivation may have been different, but that is a benefit).