The sys.monitoring and import optimisation suggestions apply as-is.

If you use standard unittest discovery the third item might apply as well, though probably not to the same degree.

I don’t think unittest has any support for distribution so the xdist stuff is a no.

On the other hand you could use unit test as the API with Pytest as your test runner. Then you can also use xdist. And eventually migrate to the Pytest test api because it’s so much better.