Do you unit, integration and e2e test MVPs?

The biggest benefit is helping spot bugs during future changes. If the project dies with the mvp, you don’t get those benefits.

I test anything security related a lot though

Some complicated parts like security etc. They have to be right no matter what.

I also migrated towards a monorepo for all my MVPs as it facilitates code reuse.

For me, that depends on the scope of the MVP.

Something simple that has very limited complexity and where bugs can be tolerated can often be cranked out fairly loosely, with only manual testing.

A more complex product in a space where bugginess has a greater likelihood of turning off potential customers, I’ll usually do unit testing on critical functionality and core UX flow, but usually skip integration and e2e.