We add support by project, and the prototypical project we started with had 1M test reverse dependencies, a quarter of that was eligible test targets that we could recommend (based on language written in). This is probably the biggest project that we would ever find to support in the monorepo.

Some are UI tests, but we don't recommend those, because we found they don't catch breakages as often so we don't support the language they're written in. The tests we recommend are often integration type tests in that they call very higher order functions and often many of them.