Join Date: Oct 2006
Location: London, UK
Programs: BA Gold, VS Silver, SQ Silver, IHG Plat Amb, Hilton Gold, Marriott Plat, Accor Silver, Radisson Prem
Posts: 16,880
You can only check-in with the operating carrier, so therefore you will have to wait for the CX desks to open.
The Fast Track lane opposite BA First check-in is for BA and OpenSkies premium passengers only. There is another Fast Track lane adjacent to the regular security screening area, which will bring you out conveniently next to the Galleries First and Club lounges.