Not to hijack the original question, but what about an engine in a closed engine box? I've seen where the breathers are routed back to the carb, and understand the rational, but is there a better or more cosmetically appealing way?
The outlet side of PCV valve must go to a low pressure (vacuum) source, so the options are somewhat limited. I don't know if it would work well with the venturi tube of a pan evac system, or a PCV outlet, placed in a through transom exhaust system, that is a good question.
Tommy