i don’t think the Covent Garden one is a pro store, just freestanding.
pro store is one of the side roads off Carnaby Street… Fouberts Place.
sign up with this site Shopping, Fashion - Carnaby London and they should send you newsletters. carnaby street has quite a lot of events on nowdays. they have started doing a 20% off in all shops for one night (including MAC) now and again… there was one last November and one earlier this year.. hopefully there will be another one in November but it’s manic, you have to get there really early or queue for ages.