Hot footing, for the leaner, meaner, fleet-of-foot flyer should take about 5-7 mins, perhaps 10 if photo-check security has longer queues.
If you've not seen the *A lounge by now, you are a total disgrace and should do so. It has dark wood, showers, warm food, cold drink and wifi. The "domestic" lounge is exactly where it was before, half its original size as of yesterday, and looks every bit as old as it is. Delicasies include cheese and crackers and Walkers biscuits. Have the Amicellis and pound cake been moved downstairs, or just done away with, anyone?
Smart money sits in the *A and leaves 15-20 mins to get to the gate, skipping the bmi "domestic" lounge entirely.