Thank you, House, for the detailed information here (and also for your info on the BD board). It's been a long time since I last flew from BRU, long before I had any *A status. But I remember BRU being one big mess.
I'll check both the SK and BD lounges. I'm not a great fan of the LH SEN lounges anyway, so I won't bother to walk over to Concourse A.