Yeah, I think I was unclear. Given a need to refactor, it's a bigger help on a bigger refactor.
But a large refactor on a large project is still a pain. By the time you get there, you still want your model stable and/or flexible enough that you don't need to do that much.
On a small enough project, every refactor is easy enough that you can lean into it. Make a bunch of assumptions you're not confident about, setting up the types so you're sure you'll know what needs fixing when they're wrong. Then you test those assumptions as you write - and run - more code.
But a large refactor on a large project is still a pain. By the time you get there, you still want your model stable and/or flexible enough that you don't need to do that much.
On a small enough project, every refactor is easy enough that you can lean into it. Make a bunch of assumptions you're not confident about, setting up the types so you're sure you'll know what needs fixing when they're wrong. Then you test those assumptions as you write - and run - more code.