[racket] Should we _always_ use `only-in` or `prefix-in` when `require`-ing packages?

In my experience, using plain require and later adding 'except-in' when a service module decides to widen its interface is a much simpler approach  than pre-emptively using 'prefix-in' or 'only-in', especially if you need (almost) everything from a (possibly large) library. -- Matthias