Hi Sparky/Karma16,
You are talking about a very different animal with your B&W's. They are designed for the plug to properly roll off the bass to integrate the subwoofer... B&W knew the outcome of your plug before you ever thought about plugging them... The principle is the same for stuffing the port on any speaker, it will roll off the bottom....period.
What it comes down to really, is, you won't cause any damage stuffing ports, if you like the results, sit in front of them and enjoy. Good Listening, Tim